US President Donald Trump has announced that US, Russian and Ukrainian officials will meet at a security conference in Munich today to discuss how to end the war in Ukraine.

"Russia will be there with our people," the US president said. "Ukraine is also invited, by the way, I don't know exactly who will be there from any country - but high-level people from Russia, from Ukraine and from the United States."

However, Russia, which is not officially participating in the annual forum in Germany, did not comment and a senior Ukrainian official said that "talks with the Russians in Munich" were "not expected".

America's NATO allies are still reacting to Trump's surprise announcement this week that he and Russian President Vladimir Putin had agreed in a phone call to begin talks to end the war.

The US president announced the trilateral meeting in Munich during a press conference on Thursday, without giving further details.

However, Zelensky's adviser Dmytro Lytvyn told reporters that the Ukrainian delegation had no plans to attend such a meeting.

Russia did not immediately respond to a BBC request for comment on the matter.

Trump's announcement came a day after he held separate calls first with Putin, then with Zelensky.

Describing the talks as "excellent," Trump said there was "a good opportunity to end that terrible, very bloody war."

But he said it was "not practical" for Kiev to join the NATO military alliance and also "impossible" for Ukraine to return to its pre-invasion borders in 2014.

Zelensky, who admitted that it was "not very pleasant" that Trump had spoken to Putin before him, warned that Ukraine would not agree to any peace deal proposed by the US and Russia without Kiev's involvement.

Zelensky said European allies "should also be at the negotiating table," amid growing fears across the continent that Trump's opening to Putin could lead to a separate US-Russia deal over the future of Ukraine and Europe.

French President Emmanuel Macron told the Financial Times that only Zelensky could negotiate on behalf of his country with Russia, warning that a "peace that is a capitulation" would be "bad news for everyone."

EU foreign policy chief Kaja Kallas said: "Any quick fix is ​​a dirty deal."

It may be a bitter pill for Zelensky to swallow, but the kind of additional US military aid to Ukraine that he would ultimately need to continue the war seems unlikely at this point, the BBC reports.

Neither Trump nor Trump's Republican Party in Congress has much interest in continuing support.