NATO’s European leaders aim to convince Donald Trump on Wednesday to re-commit to the military ​alliance at a summit in Ankara after the US president revived his disputes with them over the Iran war and Greenland.

Following his ‌arrival in the Turkish capital on Tuesday, Trump said he might have boycotted the summit had it not been for his friendship with the host, President Tayyip Erdogan, and he did not rule out further troop withdrawals from Europe.

Earlier in the day, NATO sought to demonstrate that its European members were heeding Trump’s ​calls to spend more on their own defence and rely less on the US by unveiling a raft of arms deals, worth at ​least $50 billion.

Trump, who has harshly criticised NATO during both his first and second terms in office, said ⁠he was “very disappointed” with the alliance and that the US was not “treated well“ during the US-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 ​Erdogan.

Trump has accused European nations of failing to let US forces use their airspace and bases on their territories during the war.

European officials have said they largely honoured their commitments to US forces, despite not having been consulted about a conflict that roiled their economies and was deeply unpopular in Europe.

Trump targets former ally Meloni with criticism

In recent weeks, Trump has singled out Italian Prime Minister Giorgia Meloni – formerly a close ally - for criticism.

On Tuesday, Trump said ​his relationship with Meloni “became a little bad because she refused to help us” with Iran while also describing her as a “nice person”.

Italian officials have sought ‌in recent ⁠days to draw a line under the spat.

Trump also said Greenland, a semi-autonomous territory of NATO member Denmark, should be controlled by the United States.

Hours later, also speaking in Ankara, Danish Prime Minister Mette Frederiksen said she expected allies to respect the sovereignty of the Danish kingdom and accept that Greenland was not for sale.

Summit declaration affirms commitment to collective defence

The 32 NATO leaders met for a dinner on Tuesday evening ​, but the main session of their ​summit takes place on Wednesday.

Ambassadors ⁠from all NATO members have approved a summit declaration that affirms an “ironclad commitment” to collective defence.

But the declaration will only be issued after it has been endorsed by the leaders.

The Trump administration has pressed ​Europeans to boost defence spending and take on primary responsibility for the conventional defence of Europe ​as it seeks to ⁠shift its military focus to the Indo-Pacific.

The US has also announced troop withdrawals from Europe, cut the forces it assigns to NATO’s defence plans – including an aircraft carrier, refuelling aircraft, fighter jets and drones - and launched a six-month review of its military presence on the continent.

European leaders say they ⁠are working ​to take on more responsibility for the continent’s security but want a predictable ​and orderly transition to avoid any gaps in their defences that could be exploited by Russia.

European officials have said they hope Trump’s regard for Erdogan and his good relationship ​with NATO Secretary General Mark Rutte would help smooth over tensions at the summit.