When he was elected, US President Trump gushed about him being "the first American pope".

Now it appears that warmth has faded as Chicago-born Pope Leo XIV, who was elected last May, continued his criticism of the US President's war in the Middle East.

The American president launched an extraordinary spray on the pontiff after the Pope blasted Trump's Iran vow that "a whole civilisation will die tonight."

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While the Vatican has a tradition of diplomatic neutrality, the Pope said the US President's vow was "truly unacceptable", adding any attacks on civilian infrastructure violate international law.

"Today as we all know there was this threat against all the people of Iran. This is truly unacceptable," Leo said as he left his country house in Castel Gandolfo, south of Rome.

Trump has now called the Pope "weak" and "terrible" and made confusing claims related to COVID, Venezuela and Barack Obama.

In a rant on his site, Trust Social, Trump said the pope was "weak on crime" and "terrible on social policy" before going on an incoherent rant which seemed to criticise the church over "arrests" during COVID involving social distancing.

"I like his brother Louis much better than I like him because Louis is MAGA," he said.

"We don't like a pope that says it's okay to have a nuclear weapon," he later told reporters."I don't like it. I'm not a big fan of Pope Leo."

He also said "I don't want a Pope who criticizes a president of the United States because I am doing exactly what I was elected in a LANDSLIDE to do."

Trump also brought up Venezuela, which the US attacked in January, in his remarkable post.

"I don't want a Pope who thinks it's OK for Iran to have a Nuclear Weapon.

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"I don't want a Pope who thinks it's terrible that America attacked Venezuela, a Country that was sending massive amounts of Drugs into the United States and, even worse, emptying their prisons, including murderers, drug dealers, and killers, into our Country," he said.

He also claimed Leo was only chosen because he was president.

"Leo should be thankful because, as everyone knows, he was a shocking surprise.

"He wasn't on any list to be Pope, and was only put there by the Church because he was an American, and they thought that would be the best way to deal with President Donald J. Trump.

"If I wasn't in the White House, Leo wouldn't be in the Vatican."

He also claimed the Pope "meets with Obama Sympathizers like David Axelrod, a LOSER from the Left, who is one of those who wanted churchgoers and clerics to be arrested."

Axelrod was an adviser to Obama.

"We don't like a pope that says it's okay to have a nuclear weapon," Trump later told reporters.

"I don't like it. I'm not a big fan of Pope Leo."

Trump, who just days before provoked the ire of Catholics around the world by posting an AI-generated image of himself as the pope, was quick to congratulate Leo last year when he was chosen to lead the Catholic Church.

"It is such an honour to realise that he is the first American Pope," Trump, who is Christian but not Catholic said, on Truth Social.

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"What excitement, and what a Great Honour for our Country. I look forward to meeting Pope Leo XIV. It will be a very meaningful moment!"

Trump attended the funeral of Pope Francis.

The American pope has also recently urged Americans and other "people of good will"to contact their political leaders and congressional representatives to demand they reject war and work for peace.

He used his Easter appeal to plea for "peace and to reject war, especially a war which many people have said is an unjust war, which is continuing to escalate, and which is not resolving anything."

Leo has also publicly named Trump in saying he hoped the US president was truly "looking for an off-ramp."

Also last week Leo didn't cite Trump by name but in comments in English he urged people to contact their political leaders and congressional representatives "to ask them, tell them to work for peace and to reject war."

He said the message to political leaders should be: "Come back to the table, let's talk, let's look for solutions in a peaceful way and let's remember especially the innocent children, the elderly, sick, so many people who have already become or will become victims of this continued warfare."

The Vatican is particularly concerned about how the Iran conflict has spread to a renewed war in Lebanon between Israel and the Iranian-backed Lebanese militant Hezbollah group.

The Vatican fears for Christians in southern Lebanon.

The Pentagon has said reports of a meeting between senior Department of Defence officials and the Vatican's representative in the US are "highly exaggerated and distorted".

The Free Press reports the Pentagon summoned Cardinal Christophe Pierre for a meeting with Under Secretary of War for Policy Elbridge Colby.

At the January meeting, Pentagon officials reportedly criticised a speech made by Pope Leo XIV and told the cardinal the Vatican needed to get on board.

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