The US pontiff repeated his calls at the end of the Angelus prayer for a ceasefire in Ukraine following a Russian attack on Kyiv on Thursday in which at least 25 people died, including four children.

He also noted the recent shooting during a school mass in Minnesota in the United States, in which two children were killed.

"We include in our prayers the countless children killed and injured every day around the world. Let us plead God to stop the pandemic of arms, large and small, which infects our world," he said in English.

On Ukraine, the pope said he urged the world "not to give in to indifference" and renewed his "insistent call for an immediate ceasefire and for a serious commitment to dialogue".

"It is time for those responsible to renounce the logic of arms and embark on the path of negotiation and peace, with the support of the international community," he said.