Pope Francis joined an international chorus urging Donald Trump to meet U.S. commitments on climate change in talks at the Vatican Wednesday.

Francis gave the U.S. president a copy of his 2015 encyclical calling for urgent, drastic cuts in fossil-fuel emissions after a half-hour meeting in his private study.

Francis’s choice of gift suggests he is adding his voice to those pressing Trump not to renege on the Paris accord, which is the cornerstone of global efforts to limit climate change. The Vatican said in a statement that the talks focused on international affairs and the promotion of peace, with particular emphasis on health care, education and immigration.

“Thank you, thank you,” Trump told Francis as they shook hands after the meeting. “I won’t forget what you said.” Trump has said climate change might be a hoax perpetrated by the Chinese.

For his part, Trump gave Francis a special edition of the works of U.S. civil rights leader Martin Luther King.