The parents of kidnapped American journalist Austin Tice have appealed again for his release, voicing gratitude for Pope Francis' words on behalf of all abducted victims in the Syrian conflict.

"It is a tremendous comfort to know the Holy Father is praying for the people of Syria, and that he has personally appealed to the humanity of kidnappers to release their victims," Marc and Debra Tice of Houston, Texas told CNA June 3.

On Monday, Pope Francis denounced the "scourge of kidnapping" in Syria and appealed to captors' humanity to free the victims. Those recently abducted in the country include two Orthodox Christian bishops.

The Pope's message was personally relevant to the Tices, whose son Austin disappeared in August 2012 near the Damascus suburb of Daraya where he was reporting on the Syrian conflict. Austin, a 31-year-old former Marine Corps captain and Georgetown University graduate, was working as a freelance reporter for the Washington Post and McClatchy News Service.

The Tices said their son, the oldest of seven children, is "all Texan: big, loud and friendly." They noted how his photographs of Syrians, especially local children, show "his respect for the humanity of the Syrian people."

"From what we've heard, his respect was reciprocated," they said. "You could hear in his voice how happily and deeply he was engaged in his work."

Austin Tice has now been missing for more than nine months.

His parents do not know for certain who is holding him captive, and recent developments in the Syrian conflict could affect Austin's future.

Debra Tice said that the situation of the Daraya area has recently been "very fluid" as opposition groups and the Syrian government contest control.

"We feel this could increase his chances of escape or rescue and ask everyone in the area to be aggressively searching for him in order to secure his safe return to us," she explained.

"Additionally, the upcoming U.S.- and Russian-led peace talks scheduled in Geneva offer an opportunity for discussion by all parties regarding the release of captives."

Marc Tice also saw some hopeful signs. "The best development in the past few months has been the commitment we've received from more than one Syrian official," he said. "They've told us and others that the Syrian government will do everything it can to locate Austin and return him safely.

"We have been assured through many channels that Austin is alive and being treated well, yet we have no concrete evidence of who is holding him or how to secure his release and return."

In September 2012 a 47-second video of the journalist was posted on a pro-Syrian government website and appears to implicate Islamic militants in the kidnapping. The clip shows Austin blindfolded in the custody of armed men as he tries to recite in Arabic the shahada or Muslim declaration of faith, the Associated Press reported. He then switches to English and says "Oh Jesus. Oh Jesus."

Some critics of the video have said it appears to be staged, possibly by pro-Syrian government forces who want to discredit the opposition, the Christian Science Monitor wrote in December 2012.

The Czech embassy, which is representing the U.S. in Syria after its own embassy closed in 2011, in December said its sources believe Tice is being held captive by the Syrian government. The Syrian government, however, denied those reports.

Syria's contradicting stories are part of what drew Austin Tice to the country. His father said he was among those who sought to find the truth about the two-year-old conflict between supporters and opponents of the government of President Bashar Assad.

"Austin told me he was frustrated by early reports out of Syria which couldn't be confirmed because no verifiable reports were available," Marc said.

"He told me he believed the story of this conflict needed to be told and that he believed he had the skills to do it. Considering the recognition and awards he's received for his work, I'm inclined to believe he was right."

Since his kidnapping, Tice has been awarded the George Polk Award for War Reporting and the McClatchy President's Award for Journalism Excellence.

Austin's parents said their son did not join them in converting to Catholicism in 1999, but he was raised with "a firm foundation in the Christian faith."

"He has memorized a great deal of Holy Scripture and learned the Catechism," his parents said. "He enjoyed listening to theological discussions on Christian radio. In times of stress and trouble, he relies on the unwavering love of God."

Debra reflected that her faith has helped her during this time of uncertainty.

"I firmly believe God is in control and pray for His will to be done. I know it is God's desire for all people to live in peace. I pray constantly for an outpouring of mercy to restore peace to our family, to Syria, the Levant, and the entire world," she said.

She also noted the positive effect of knowing that people around the world are praying for Austin and the Tice family. "These prayers give us hope and strength; undoubtedly they are also a source of great comfort for our son."

Marc said that the kidnapping of his son "has challenged the foundations on which my faith has been built – much of which I am sure needed to be challenged."

"As a convert to Catholicism, I was especially drawn to the way the Church expressed faith as a journey, and how understanding and enlightenment was not necessarily a flash of brilliance, rather a life-long process. I trust this part of my journey will leave me not only changed but stronger," he said.

Debra voiced her love in a message directed to her son, saying: "We work and pray daily for your safe return. Do not despair; remain steadfast in faith."

Both parents urged their son's captors to keep him safe and treat him well. "Have compassion on us and let him come home," Marc said.

The Tice family asks anyone with information about Austin to contact them through their website,