In 1999, two teenagers froze to death in the hold of a Sabena Airlines Airbus A330 travelling from Guinea to Brussels.

Yaguine Koïta and Fodé Tounkara were found three days after their death among their possessions, including plastic bags with birth certificates, school report cards, family photographs and a letter, written in imperfect French.

The letter addressed the leaders of Europe, asking them to help children in Africa receive a better education and to provide relief from hunger and war.

"Therefore, if you see that we have sacrificed ourselves and risked our lives, this is because we suffer too much in Africa and that we need you to fight against poverty and to put an end to the war in Africa," it reads. "Nevertheless, we want to learn, and we ask you to help us in Africa learn to be like you."

Fifteen years after their death, the world has seen an unprecedented increase in the number of unaccompanied child migrants, particularly along the border between Mexico and the United States, and on the Mediterranean Sea, known as the "gateway to Europe" for those migrating from Africa.

Caritas Internationalis, a Catholic non-profit helping the poor throughout the world, hosted a panel with Vatican Radio Nov. 18 to discuss the rights of child migrants, and the responsibilities of countries taking them in as part of the 25th anniversary of the United Nation's Convention on the Rights of the Child (UNCRC).

The UNCRC defines a child as anyone under 18 years of age and outlines certain rights that children – including migrants - should enjoy, including: the right to life, health care, education, to practice their own religion, and the right to play.

Panelist Msgr. Bob Vitillo, who serves as Caritas' representative to the United Nations, said ensuring the rights of child migrants is important because they are often the most vulnerable to abuse and neglect.

"Many of them are excluded from school, many of them don't benefit from the health plans and the programs in the country, many of them are street children and therefore are much more vulnerable to being sexually abused or abusive work situations," he said, "so these are children who especially need to have their rights assured."

The UNCRC has been ratified almost universally, except for in the United States, Somalia, and South Sudan. Those opposed to U.S. ratification cite concerns about U.N. intervention in domestic politics, as well as concerns regarding the rights of parents.

According to the Migration Policy Institute, the United States alone has seen the number of unaccompanied child migrants almost triple in a few short years. In the fiscal year of 2011, border patrolmen apprehended 16,067 unaccompanied children. In just the first eight months of 2014, they arrested 47, 017.

Panelist Sister Norma Pimentel said she knows the "horrible and heartbreaking" plight of child migrants on the border all too well. As the Executive Director with Catholic Charities in the Rio Grande Valley, she has often pleaded with border patrolmen to let her into the detention centers where families and children are kept.

"A great number of them were children, dirty and crying and just packed completely in cells," she said. "There was no room even for them to breathe, and the children would say 'Please help me, I can't breathe, I need your help,' and all their faces filled with tears, it was so sad to see."

Sister Pimentel said border facilities have been bursting with the recent upsurge in immigrants, and the presence of sisters and Catholic Charities workers can help overwhelmed patrolmen see the humanity in the migrants.

"We just ask them, 'Please let us be there, present, as Church for the children,'" she said. "We pray with them, and the officer is telling me, 'Sister, thank you for helping us realize they're human,' because they were just so hardened because of the great number of children they were seeing and they didn't know what to do."

The reason for the immigration increase is difficult to pinpoint. Some blame an increase in violence and sex-trafficking in Central America, while others point to lax immigration enforcement policies that lure more people to the United States. Likely, it's a combination of factors influencing the sudden upsurge in people, and especially children crossing the border.

Some children who make it to the United States find refuge under the Trafficking Victims Protection Reauthorization Act, through which they are transferred by the Border Patrol into the custody of the Office of Refugee Resettlement (ORR), an agency of the U.S. Department of Health and Human Services responsible for processing and sheltering certain unaccompanied minors.

Others are deported almost immediately, although that doesn't necessarily stop them from trying to cross multiple times.

According to data from the Migration Policy Institute, ninety percent of children from Central America are released by ORR into the care of a parent, relative, or family friend while they await adjudication of their immigration cases, with foster care the placement for the remainder. But this process can take several days or weeks, leaving many children in the limbo of detention centers.

Msgr. Vitillo said often, children are not aware of their right to plead their case to stay in the country in which they've arrived.

"I know there are many legal advisors (with Catholic Charities) that try to have contact with the children and let them know of their rights and then also arrange for legal assistance to present their cases," he said. "But in many of the cases, where they're being kept in detention, they don't even have the chance to present those claims so that's the first thing, to be able to show that they need to stay in the country where they are now because of their need for protection."

Detention of child migrants, even for short periods of time, can be detrimental to their health and well-being, said panelist Jem Stevens, who works for child migrants' rights as the Regional Coordinator of the International Detention Coalition.

"The Committee on the Rights of the Child has said in 2012 that immigration detention is never in a child's best interest and will always constitute a child's rights violation," she said.

The good news is that there are alternatives to detention, and that they are about 80 percent cheaper for governments to implement, she added.

"What we try to do is work with our members and with states to assist governments to implement these non-custodial, community based alternatives which can really better protect the welfare and rights of children while allowing the states to achieve their migration management goals, and while being a lot more cost-effective," she said.

Fortunately, there has been a strong global movement away from the use of child migrant detention, Stevens said.

Msgr. Vitillo said besides the physical downsides of detainment, a child's emotional health must also be taken into account.

"Sometimes people think the parents send their children unaccompanied to other countries are irresponsible…but most of the time it's an act of love because of the violence and chaos that's going on in their own country, and so they feel that this is the only way for their child to survive," he said.

"The child arrives here, many times knows no one, many times is being abused or exploited by the person who brought them across different borders….and then they're terribly lonely and feel completely overwhelmed, and it's only when we have organizations such as Caritas and Catholic Charities and other faith based, non-governmental organizations that they can begin to develop some trust," he continued.

Panelist Nigel Baker, British Ambassador to the Holy See and a father himself, said the United Kingdom and other European states have policies in place to protect children from detainment and to keep families together.

"From the U.K. point of view we have a policy of always trying to always keep families together, and since 2012 within the immigration rules specifically on immigration there is a principle of consideration of the best interest of the child throughout the system," he said.

"In Belgium they provide a legal guardian, who immediately when the child arrives they provide the support and advice that a child needs in those earlier and future days," he said. "In the U.K. our policy is that a child is taken by a social worker, who provides that support and guarantees that any unaccompanied child migrant regardless of nationality or status will receive at the very least the minimum statutory care that any child who is under British law."

Baker said as a father himself, he can't imagine the desperation and the love of parents who send their children off into the unknown in hopes of a better future. He added that solving the issues in the countries of origin is equally as important as caring for immigrant children.

"Ultimately…we like to support people in their own country so they don't have to make this terrible journey," he said. "But it's essential that countries receiving these children ensure that they can implement the requirements under the CRC, and provide these children with a decent life for as long as….they're in the country in which they arrived."  

In what is seen as a highly-contentious move, U.S. President Barack Obama announced last week that he would stay the deportation of certain undocumented immigrant parents for up to three years, allowing them to work legally. Eligibility requirements include having lived in the U.S. for at least five years, having children who are U.S. citizens or legal residents, passing a criminal background check and agreeing to pay taxes.

Roughly 4 million people will likely qualify for this measure, while thousands of others will benefit from other changes. The president extended benefits of temporary residence to more children of undocumented immigrants, expanding the eligibility for the Deferred Action for Childhood Arrivals (DACA) program and extending their temporary stay from two to three years.

The executive order, which was issued a few days after the panel, has been both praised for keeping families together, and slammed for not being passed through Congress.

As Catholics, Msgr. Vitillo said there are several things the lay faithful can do to support these children.

"First of all, we need to pray for the situations in their home countries, that they will be resolved, that true integral human development will come throughout the world, also that the conflicts and the wars and the violence will be ended throughout the world, and we all have a part to play in that," he said.

"We (also) have a part to play as citizens, in our own countries, that our governments do have good policies and are implementing those policies. If we're voters, then we need to make sure that we show the power of the vote in demanding that our governmental leaders follow through on these things."

"And then we need to get involved in supporting Caritas, Catholic Charities, other organizations that are helping these children, and then also open up our homes to these children, some of them need foster care, we can give them the family love that they're missing right now from their biological parents, in the hope that they can someday be reunited with their families."

Stevens added that the most important thing to remember is the humanity of the children involved in immigration.

"We need to remember that children are first and foremost children, that their best interest must first and foremost be prioritized over migration policies, and we people need to get involved."

To watch the full panel, visit: http://www.caritas.org/what-we-do/migration/child-migration/