Emmanuel Macron has said there is “no mistrust” between Europe and the US, a day after a report claimed the French president had warned privately there was a risk Washington could betray Ukraine.

“Unity between Americans and Europeans on the Ukrainian issue is essential. And I say it again and again, we need to work together,” Macron told reporters during a visit to China on Friday.

“We welcome and support the peace efforts being made by the United States of America. The United States of America needs Europeans to lead these peace efforts,” he said.

The German magazine Der Spiegel on Thursday cited a leaked summary of a confidential call between several European leaders in which Macron and the German chancellor, Friedrich Merz, voiced fundamental doubts about US efforts to negotiate between Ukraine and Russia.

The transcript quoted Macron as warning Ukraine’s president, Volodymyr Zelenskyy, that “there is a chance that the US will betray Ukraine on territory, without clarity on security guarantees”.

The alleged leak risked angering Donald Trump, whom European leaders have been at pains to flatter, knowing he is the key player in any mediation efforts with Moscow.

It also came as European leaders rushed to salvage a sorely needed financing plan for cash-strapped Ukraine. Merz held emergency talks on Friday with the European Commission president, Ursula von der Leyen, and Belgium’s prime minister, Bart De Wever.

When asked about the Spiegel report on Friday, Macron responded: “I deny everything.”

Der Spiegel said it had obtained the English summary of Monday’s call, featuring what it said were direct quotations from heads of government.

In the transcript, Macron described the current tense phase of the negotiations as harbouring “a big danger” for Zelenskyy. Merz reportedly added that he needed to be “very careful”.

“They are playing games with both you and us,” Merz was reported as telling Zelenskyy – a remark believed to refer to a diplomatic mission to Moscow this week by Trump’s envoy Steve Witkoff and the US president’s son-in-law Jared Kushner.

Washington presented a 28-point proposal last month to halt the war in Ukraine, drafted without input from Ukraine’s European allies and criticised as too close a reflection of Moscow’s maximalist demands.

US and Ukrainian negotiators have since held talks before Witkoff and Kushner headed to Moscow on Tuesday. The pair spent five hours in talks with Vladimir Putin at the Kremlin and Witkoff then met Ukraine’s national security council chief, Rustem Umerov, in Miami on Thursday. There was no official readout of the Miami meeting and a Ukrainian official said there were to be further talks in the Florida city on Friday.

Moscow and Kyiv have continued to fight, seeking stronger negotiating positions. Russian drones struck a house in central Ukraine on Thursday night, killing a 12-year-old boy, officials said, while long-range Ukrainian strikes reportedly targeted a Russian port and oil refinery.

Merz will dine in private on Friday with von der Leyen and De Wever, who has expressed opposition to a scheme to fund Ukraine that involves the unprecedented use of frozen Russian assets.

With Russia’s attacks intensifying, Kyiv is running out of money. The EU has pledged to keep Ukraine afloat next year and intends to raise €90bn (£80bn) to meet about two-thirds of its needs for 2026 and 2027.

Von der Leyen has proposed two main options to raise the funds. The bloc could either borrow against its shared budget on the international markets, she said this week, or issue a loan secured by immobilised Russian assets – mainly held in Belgium – that Kyiv would repay from Russia’s postwar reparations.

De Wever, however, told an event in Brussels this week that he was against seizing frozen Russian assets. It was “a nice idea, stealing from the bad guy to give to the good guy”, he said. “But stealing the frozen assets of another country has never been done.

“Even during the second world war, we did not confiscate Germany’s money.”

In an op-ed in the Frankfurter Allgemeine newspaper on Thursday, Merz told his fellow EU leaders that the decisions they made over the coming days would “decide the question of European independence”.

Moscow’s ambassador to Germany, Sergei Nechaev, said in a statement: “Any operation with sovereign Russian assets without Russia’s consent constitutes theft. It is also clear that the theft of Russian state funds will have far-reaching consequences.”