There can be no negotiation “about Ukraine without Ukraine”, the UK’s defence secretary has warned.

John Healey was speaking ahead of a Nato meeting of defence ministers in Brussels on Thursday after US President Donald Trump and Vladimir Putin agreed to begin negotiations to end the war.

Healey told reporters: “We’ve seen the calls from President Trump overnight and we all want to see a durable peace and no return to conflict and aggression.”

But he added that Russia “remains a threat well beyond Ukraine”.

He told reporters that “my message… Will be that there can be no negotiation about Ukraine without Ukraine and Ukraine’s voice must be at the heart of any talks”.

It is becoming harder for Nato to keep a united front on Ukraine, with Trump’s unilateral efforts to bring an end to the war.

In a post on his Truth Social platform, Trump said he and the Russian president had “agreed to have our respective teams start negotiations immediately”.

He did not set a date for a face-to-face meeting with Putin, but later told reporters at the White House: “We’ll meet in Saudi Arabia.” He wrote on social media the pair had also invited each other to their respective capitals.

The head of the Alliance, Mark Rutte, is still trying to hold the line – saying that allies must step up their military support for Kyiv and that Ukraine must be involved in any peace talks. But in reality Washington is now making the calls.

That one phone call between Presidents Trump and Putin, due to be followed up by a meeting, has pushed Nato to the sidelines.

Some defence ministers are trying to convey the message that nothing has fundamentally changed and Healey has again repeated the familiar lines that Nato would remain focused on keeping Ukraine in the fight and “put them in the best position to secure a lasting peace through strength.”

On Wednesday, US Defence Secretary Pete Hegseth said European nations must provide the “overwhelming” share of funding for Ukraine.

Speaking to reporters ahead of the meeting on Thursday, Hegseth said the US’s attempts to negotiate peace between Ukraine and Russia was “certainly not a betrayal” of the Ukrainian soldiers who have been fighting against the invasion.

Addressing fellow defence chiefs later, he added that the US was “committed to expediting the process” of foreign military sales, to ensure “our allies get what they need when they need it”.

Healey said the UK had “heard a clear message from the US about stepping up and we are”, pointing out a new £150m package of military aid including drones, tanks and air defence systems for Ukraine.

“The Ukrainians are fighting bravely,” said Healey. “Its our jobs as defence ministers here at Nato to put them in the best position to secure a lasting peace through strength.”

The US indicated that it was unlikely Ukraine would return to its pre-2014 borders under a deal, while there was not a realistic prospect of Ukraine joining the Nato military alliance.

Nato members have previously pledged their support for an “irreversible path” to future membership for Ukraine.

Healey said on Wednesday that welcoming the country to Nato would take “some time”, emphasising that the focus “for now” should be on ensuring Kyiv was in a strong position ahead of potential peace talks.

Reform UK leader Nigel Farage also voiced his support for Ukraine joining the alliance, telling GB News the move was “essential”.

But Nato solidarity and strength has been weakened by the clear message from Washington – that in trying to bring an end to the war, it is not prepared to bankroll military support for the Kyiv, or allow Ukraine to join Nato.

Nor does it believe Ukraine should expect the return of all its territory lost to Russia. It’s a very different message.

Rutte is trying to salvage some credibility by urging allies to dramatically ramp up defence spending. That, he hopes, will build bridges and influence with Washington.

But President Trump has set a very high bar that few can meet – spending up to 5% of their GDP on defence. Most allies struggled to meet the 2% target set over a decade ago.

So far criticism of Donald Trump has been muted. But that carefully calibrated united Nato front on Ukraine – that has survived until now – is fraying. So are efforts to keep President Putin isolated as an international pariah.

The German Defence Minister, Boris Pistorius, has been braver than most. He said “he regretted” that the US administration had already made concessions to Russia before the talks had started.