Pope Leo decried conditions for Palestinians in Gaza in his Christmas sermon on Thursday, in an unusually direct appeal during what is normally a solemn, spiritual service on the day Christians across the globe celebrate the birth of Jesus.

Leo, the first US pope, said the story of Jesus being born in a stable showed that God had "pitched his fragile tent" among the people of the world.

"How, then, can we not think of the tents in Gaza, exposed for weeks to rain, wind and cold?" he asked.

Leo, celebrating his first Christmas after being elected in May by the world's cardinals to succeed the late Pope Francis, has a quieter, more diplomatic style than his predecessor and usually refrains from making political references in his sermons.

In a later Christmas blessing, the pope, who has made care for immigrants a key theme of his early papacy, also lamented the situation for migrants and refugees who "traverse the American continent".

Leo, who has in the past criticised US President Donald Trump's immigration crackdown, did not mention Trump. In a Christmas Eve sermon on Wednesday, the pope said refusing to help the poor and strangers was tantamount to rejecting God himself.

Leo decries 'rubble and open wounds' of war

The new pope has lamented the conditions for Palestinians in Gaza several times recently and told journalists last month that the only solution in the decades-long conflict between Israel and the Palestinian people must include a Palestinian state.

Israel and Hamas agreed to a ceasefire in October after two years of intense Israeli bombardment and military operationsthat followed a deadly attack by Hamas-led fighters on Israeli communities in October 2023. Humanitarian agencies say there is still too little aid getting into Gaza, where nearly the entire population is homeless.

In Thursday's service with thousands in St. Peter's Basilica, Leo also lamented conditions for the homeless across the globe and the destruction caused by war more generally.

"Fragile is the flesh of defenceless populations, tried by so many wars, ongoing or concluded, leaving behind rubble and open wounds," said the pope.

"Fragile are the minds and lives of young people forced to take up arms, who on the front lines feel the senselessness of what is asked of them and the falsehoods that fill the pompous speeches of those who send them to their deaths," he said.

Pope laments conflicts in Ukraine, Thailand, Cambodia

In an appeal on Thursday during the "Urbi et Orbi" (to the city and the world) message and blessing given by the pope at Christmas and Easter, Leo called for an end to all global wars.

Speaking from the central balcony of St. Peter's Basilica to thousands of people in the square below, he lamented conflicts, political, social or military, in Ukraine, Sudan, Mali, Myanmar, and Thailand and Cambodia, among others.

Leo said people in Ukraine, where Russian troops are threatening cities critical to the country's eastern defences, have been "tormented" by violence.

"May the clamour of weapons cease, and may the parties involved, with the support and commitment of the international community, find the courage to engage in sincere, direct and respectful dialogue," said the pope.

For Thailand and Cambodia, where border fighting is in its third week with at least 80 killed, Leo asked that the nations' "ancient friendship" be restored, "to work towards reconciliation and peace".