U.S. President Donald Trump threatened to halt weapons supplies to Ukraine to pressure European allies into joining a "coalition of the willing" to reopen the Strait of Hormuz, according to sources familiar with the discussions.
Iran effectively closed the strategic strait following U.S. and Israeli attacks on the Islamic republic in late February. The blockade has choked a vital maritime route that typically handles a fifth of global oil shipments.
Last month, Trump demanded that NATO navies help reopen the narrow waterway. However, European capitals rebuffed the request, arguing that such an operation would be impossible during an active conflict and emphasizing that the confrontation was "not our war."
In response, Trump threatened to cut off supplies to Purl, NATO's European-funded weapons procurement initiative for Ukraine, according to three officials briefed on the matter.
Prompted by the threat and urged by NATO Secretary-General Mark Rutte, key alliance members—including France, Germany, and the UK—issued a hastily drafted joint statement on March 19. "We express our readiness to contribute to appropriate efforts to ensure safe passage through the Strait," the statement read.
"It was Rutte who insisted on the joint statement because Trump had threatened to withdraw from Purl and from Ukraine in general," one official explained. The source added that the statement was assembled quickly, with other nations joining later due to a lack of time to secure immediate signatures from all allies.
Rutte held multiple calls with Trump and U.S. Secretary of State Marco Rubio in the two days leading up to the declaration, two officials confirmed.
Another source noted that during a call with French, German, and British leaders, Rutte described Trump as "rather hysterical" over Europe's refusal to help secure the strait.
British officials maintained that the UK and the U.S. had been discussing military options for securing the waterway prior to March 19. However, they did not deny that Washington had threatened to pull its support for Ukraine if NATO countries failed to intervene.
Deputy White House Press Secretary Anna Kelly stated that President Trump has made his disappointment with NATO and other allies clear, adding that the president emphasized the United States will remember.
Trump has repeatedly criticized European allies for not doing more to support the U.S. war against Iran, while simultaneously framing the conflict in Ukraine as a strictly European problem.
"We're there to protect NATO, to protect them from Russia. But they're not there to protect us. It's ridiculous," Trump said during a cabinet meeting last week.
Trump also told Reuters he planned to use a Wednesday evening address to the American public to state that he would "absolutely" consider withdrawing from NATO.
A NATO official declined to comment on the specifics of Rutte's conversations with other leaders, directing inquiries to the secretary-general's March 19 public statement.
When asked about Trump's frustration with NATO allies regarding the Strait of Hormuz, Rutte remarked, "I am confident that allies, as always, will do everything in support of our shared interests."
Additional countries have signed the joint declaration since its initial release.
UK Prime Minister Keir Starmer announced on Wednesday that he will host talks this week among the 35 signatories to discuss forming a coalition to reopen the strait "after the fighting has stopped."
U.S. and Israeli operations against Iran have intensified global competition for PAC-3 interceptor missiles. These munitions, used in Patriot air defense systems, are heavily utilized by Gulf nations defending against Iranian attacks and remain vital to Ukraine's defense against Russian missile strikes.
On Friday, Rubio confirmed that U.S. military supplies to Ukraine through the Purl mechanism remain unaffected by the war in the Middle East. "Nothing yet has been diverted," he stated.
However, Rubio did not rule out the possibility that the U.S. might eventually reroute weapons earmarked for Ukraine to replenish American stockpiles depleted during the conflict with Iran.
"If we need something for America and it's American, we're going to keep it for America first," he added.