Pope Francis said yesterday that the "powerful of the Earth" should be reminded that they will one day answer to God for their care for the environment and use of the Earth's resources.

Speaking at a Mass before the opening for the Caritas Internationalis general assembly at the Vatican, he said there is no need for anyone hungry.

"The planet has enough food for all, but it seems that there is a lack of willingness to share it with everyone," the Pope said. "We ought to set the table for all, and ask that there be a table for all."

He praised the work of the Catholic development charity, and said we should do all we can to ensure that people have enough to eat. Part of that, he said, was to address global leaders about their care for the environment.

"We must do what we can so that everyone has something to eat, but we must also remind the powerful of the Earth that God will call them to judgement one day and there it will be revealed if they really tried to provide food for Him in every person and if they did what they could to preserve the environment so that it could produce this food."

The image of the "table" recurred throughout his message, including referring to the story of the jailer taking care of Paul and Silas in prison in Acts 16. He said it was what the gospel called us to do – care for the suffering and prepare a table for them.

He also pointed to the Eucharist as symbol of God feeding us today. "This is also a beautiful image that the Word of God offers us today: setting the table. Even now, God sets the table of the Eucharist."

And at the Communion table, where we think of the body of Christ, the Pope said we should remember persecuted Christians – those who have been deprived of food "for the soul". "I renew the appeal not to forget these people and these intolerable injustices," he said.

The Pope's long-awaited encyclical (papal letter to bishops) on climate change is set to be released in June or July. In April the Vatican hosted a climate change conference that concentrated on the moral imperative to care for the environment.

Previous Popes have spoken out on climate change, but Francis has made it key personal issue and has linked it with a number of other development concerns, such as migration.