US President Donald Trump threatened to cut off weapons supplies for Ukraine to pressure European allies into backing efforts to reopen the Strait of Hormuz.
The strategic waterway has effectively been closed by Iran following US and Israeli strikes in late February, disrupting a route that typically carries about a fifth of global oil supplies.
According to three officials, cited by the Financial Times, Trump pushed NATO allies to deploy naval forces to secure the strait but faced resistance from several European capitals, which argued the operation was not feasible amid ongoing conflict and “not our war.”
In response, Trump warned he could halt shipments to PURL, a NATO-backed weapons procurement initiative for Ukraine funded by European countries.
NATO Secretary-General Mark Rutte intervened, urging allies to issue a joint statement signaling support. On March 19, countries including France, Germany, and the UK said they were ready to contribute to efforts ensuring safe passage through the strait.
One official said the statement was rushed after Trump threatened to pull back not only from PURL but from broader support for Ukraine.
“The statement was then quickly put together, and other countries joined in afterwards because there was not enough time to invite everyone to sign up straight away.”
Rutte held multiple calls with Trump and US Secretary of State Marco Rubio in the days leading up to the statement, officials said.
During separate talks with European leaders, Rutte described Trump as “rather hysterical” over their refusal to commit naval forces.
The UK acknowledged military-level discussions with Washington on securing the strait but did not deny that US support for Ukraine had been used as leverage.
The White House said Trump has made clear his frustration with NATO allies, warning that “the United States will remember” their stance.
Trump has repeatedly framed the war in Ukraine as Europe’s responsibility while criticizing allies for not doing more to support US operations against Iran.
“We’re there to protect NATO, to protect them from Russia. But they’re not there to protect us. It’s ridiculous,” he said during a cabinet meeting last week.
A NATO official declined to comment on private discussions but pointed to Rutte’s public statement expressing confidence that allies would act in support of shared interests.
UK Prime Minister Keir Starmer said he would host talks among 35 countries that have since backed the March 19 statement, aimed at forming a coalition to secure the strait after hostilities end.
Meanwhile, the conflict in the Middle East is straining supplies of Patriot air defense interceptors – critical both for Gulf states and for Ukraine’s defense against Russian missile attacks.
Rubio said US military aid to Ukraine through the PURL mechanism has not yet been affected but did not rule out future diversions.
“If we need something for America, we’re going to keep it for America first,” he said.
“Paper Tiger” comments
Separately, Trump escalated his criticism of NATO, saying he is seriously considering withdrawing the United States from the alliance, which he called a “paper tiger.”
“It’s beyond reconsideration,” Trump told The Telegraph. “I was never swayed by NATO. I always knew they were a paper tiger, and [Russian leader Vladimir] Putin knows that too.
The remarks mark one of Trump’s sharpest attacks yet on the alliance and underscore a widening rift between Washington and its European partners.
Trump framed allies’ refusal to support US operations against Iran as a failure of burden-sharing.
“We’ve been there automatically, including Ukraine… They weren’t there for us,” he said.
Secretary of State Rubio echoed the criticism, saying Washington may “re-examine” its relationship with NATO after the conflict.
“If NATO is just about us defending Europe if they’re attacked, but them denying us basing rights when we need them, that’s not a very good arrangement,” Rubio said.
The standoff has revived debate around NATO’s Article 5 mutual defense clause, which applies only if a member state is attacked – not in offensive operations such as the current conflict with Iran.
Despite Trump’s threats, any move to withdraw the US from NATO would face legal hurdles. A 2023 law requires congressional approval before a president can exit the alliance.