Donald Trump is reportedly considering advocating for a controversial “pay-to-play” overhaul of NATO that could see countries that fail to meet defence spending targets banned from key votes, including when the bloc goes to war. The US President is said to have been weighing up proposals that would fundamentally reshape how the 32-country alliance operates, linking influence more directly to financial contributions.

Under the proposal, NATO members that do not meet a 5% defence spending target could be excluded from major military and strategic decision-making. This is one of several plans Mr Trump is reportedly thinking about after allies rejected his demand to send warships to reopen the Strait of Hormuz, including a plan which could see the removal of American troops from Germany.

Under current rules, NATO members spend at least 2% of their GDP on defence, following Mr Trump’s demand to double military funding in 2018. The alliance’s secretary-general, Mark Rutte, said leaders would have to set out plans for reaching the new 5% target at a summit in Ankara, Turkey, later this year.

“The frustration we’ve had with the Europeans has been very real,” an administration source told The Telegraph. “Any country that’s not paying 5% shouldn’t be allowed to vote on future expenditures at NATO.”

If Mr Trump’s proposal were to become a reality, NATO allies that fail to meet the new target could be frozen out of decisions on expansion, joint missions and triggering the Article 5 mutual defence clause.

“You shouldn’t be able to vote to spend future money if you’re not paying,” a US source added. “We need to start the conversation about what is a threat and what does the alliance do. We have to send the message that what Spain and the UK did is unacceptable.”

Three NATO officials told The Telegraph that US envoys had not formally tabled the plans at the alliance’s headquarters in Brussels. However, one source acknowledged that they had been pushing for a “pay-to-play” model in several discussion forums.

The change would also need consensus from other NATO members, but allies are likely to block any changes to the process, risking further clashes with Mr Trump.

This comes after the US President ordered thousands of troops to the Middle East after NATO countries refused to send ships to the Strait of Hormuz. Mr Trump has previously threatened to pull the US out of the alliance altogether amid frustration over Europe and the UK’s lack of support for the conflict in the Middle East.

Sources close to the president said Mr Trump’s relationship with Sir Keir Starmer deteriorated after he blocked the US from using Diego Garcia, the military base in the Chagos Islands: “The American people have been shocked at just how much the British Government has been unreliable. The US department of defence has been frustrated that they can’t properly partner with a country that is supposed to be our greatest ally.”