Leaders will have a busy day in Ankara on Wednesday as the NATO summit will be formally launched. The alliance's European leaders aim to convince U.S. President Donald Trump to re-commit to the military alliance after Trump revived disputes over ⁠the Iran war and Greenland and launched a new wave of strikes on Iran.

On arriving in the Turkish capital on Tuesday, Trump took swipes at allies for not standing by the U.S. on the Iran war and said he might have boycotted ​the meeting had it not been for his friendship with the host, President Recep Tayyip Erdoğan.

The U.S. ​then ⁠unleashed new military strikes on Iran and revoked a license allowing Iran to sell oil in response to attacks on three tankers. It was the latest blow to a fragile cease-fire agreement in a war that is deeply unpopular in Europe.

NATO Secretary General Mark Rutte defended the new U.S. strikes as "absolutely necessary" and played down Trump's disappointment with allies as "isolated cases." "When you have a cease-fire and Iran is basically violating the cease-fire, I think it is totally crucial that the U.S. forcefully react," Rutte told reporters before the summit.

NATO on Tuesday had sought to demonstrate that its European members were heeding Trump’s calls to spend more on their own defense and rely less on the U.S. by unveiling a raft of arms deals worth at least $50 billion. Trump, who has harshly criticized NATO during both his first and second terms in office, said he was “very disappointed” with the alliance and that the U.S. was not “treated well" during the U.S.-Israeli war on Iran. “Why are ⁠we ⁠spending hundreds of billions of dollars, and they're not there for us? We've always been there for them,” Trump said in an appearance on Tuesday alongside Erdoğan.