The US is "studying" whether to reduce the thousands of troops it has stationed in Germany, Donald Trump has announced via social media.

It comes just days after German Chancellor Friedrich Merz criticised his approach to the war in Iran, suggesting that US had been "humiliated" by Iranian negotiators.

In his post, Trump said he was "studying and reviewing the possible reduction of Troops in Germany, with a determination to be made over the next short period of time." The US has a significant military presence in Germany, with more than 36,000 active duty troops assigned to bases across the country as of last December.

The BBC has reached out to the White House for comment.

Merz made his initial remarks on Monday in an address to university students in Marsberg, telling them that "the Americans clearly have no strategy".

"The Iranians are obviously very skilled at negotiating, or rather, very skillful at not negotiating, letting the Americans travel to Islamabad and then leave again without any result," he said.

He added that the "entire nation" was being "humiliated" by the Iranian leadership.

Trump responded the following day with a post to Truth Social, where he said Merz thought it was "OK for Iran to have a Nuclear Weapon" and "doesn't know what he's talking about."

"No wonder Germany is doing so poorly, both Economically, and otherwise!" the post read.

When asked about the post in a press conference on Wednesday, Merz said the "personal relationship between the American president and myself remains just as good as before."

He has not yet responded to Trump's suggestion that he could reduce US troops in Germany.

Over the past two months, the US president has repeatedly threatened to withdraw from the 32-member Nato alliance, calling it a "paper tiger" and a "one-way street".

Earlier in April, a leaked internal Pentagon email detailed potential measures for the US to punish allies it believed had failed to support its campaign in Iran, including a suggestion that the US could seek to suspend Spain from Nato over its stance.

A Nato official told the BBC that the alliance's founding treaty "does not foresee any provision for suspension of Nato membership, or expulsion". (BBC)

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