He also noted that some countries are still deeply affected by the coronavirus and continue to have many deaths.
There is one country, he said, where on Friday "one person died per minute. Terrible!"
The pope appeared to be referencing Brazil, where on June 5, an editorial on the front page of the Folha de S.Paulo newspaper said COVID-19 is "killing a Brazilian per minute," after the country recorded 1,473 deaths in 24 hours.
According to the John Hopkins University COVID-19 dashboard, Brazil has the second-most cases of the coronavirus in the world after the United States with nearly 673,000 confirmed cases. Brazil is third in the world for deaths, with almost 36,000 recorded as of Sunday.
"I wish to express my closeness to those populations, to the sick and their families, and to all those who care for them," Francis said.
He concluded by pointing to the Church's dedication to the Sacred Heart of Jesus in the month of June. He asked everyone to repeat with him an old prayer he was taught by his grandmother: "Jesus, make my heart like unto thine."
"Indeed, the human and divine Heart of Jesus is the wellspring where we can always draw upon God's mercy, forgiveness and tenderness," he said, encouraging everyone to focus on the love of Jesus.
"And we can do this by adoring the Eucharist, where this love is present in the Sacrament. Then our heart too, little by little, will become more patient, more generous, more merciful," he said.