United States President Joe Biden has called on NATO allies to “sustain our support” for Ukraine during a visit to Berlin ahead of US elections next month that could disrupt military support for Kyiv.

Biden’s one-day visit to the German capital on Friday saw him meet Chancellor Olaf Scholz before they held four-way talks with French President Emmanuel Macron and British Prime Minister Keir Starmer, with much of the discussion focused on how to end the fighting in Ukraine as Russian forces advance in the east.

“We’re headed into a very difficult winter. We cannot let up,” said Biden on what could be his last presidential trip to Europe, with Kyiv and its allies fearing the potential re-election of Republican presidential candidate Donald Trump, who has opposed the level of US military support for Ukraine.

However, in what was likely a blow to Kyiv, the US president said the talks had yielded “no consensus” for providing Ukraine with long-range weapons that Ukrainian President Volodymyr Zelenskyy has been requesting from Western nations for months to conduct deeper strikes into Russia.

Washington and London have rejected Ukrainian requests for clearance to use donated long-range weapons against targets inside Russia. Berlin has refused to send its own long-range Taurus missile system.

“We are supporting Ukraine as powerfully as we can,” said Scholz. “And at the same time, we are making sure that NATO does not become a party to the war so that this war does not turn into an even bigger catastrophe.”

The previous day, Zelenskyy had presented his “victory plan” to the European Union and NATO, but his allies had not agreed to his request for immediate NATO membership.

In another worrying development for Ukraine, North Korea has decided to send a “large-scale” troop deployment to support Moscow’s war, according to South Korean intelligence.

Speaking at the British embassy in Berlin, Starmer said, “if this is true then to me it looks more an act of desperation than anything else.”

Trump has signalled that he would be more reluctant than Biden to continue supporting Ukraine, potentially depriving Kyiv of its biggest military and financial backer.

On Thursday, he blamed Zelenskyy for helping start the war with Russia. On the campaign trail, he has called the Ukrainian president “the greatest salesman on Earth” for having solicited and received billions of dollars of US military aid.

Biden earlier received a red-carpet welcome from German President Frank-Walter Steinmeier, who awarded him Germany’s highest honour – the Grand Cross special class of the Order of Merit – for championing bilateral and transatlantic ties.

The other issue in focus was the Middle East conflict. Biden had earlier congratulated Israel on its killing of Hamas leader Yahya Sinwar, calling it “a relief” for Israel and a step towards ending the Gaza war.