WASHINGTON — A planned summit between United States President Donald Trump and Russian President Vladimir Putin was put on hold on Tuesday, as Moscow's rejection of an immediate ceasefire in Ukraine cast a cloud over attempts at negotiations.

A senior White House official told Reuters, "there are no plans for President Trump to meet with President Putin in the immediate future", after Secretary of State Marco Rubio and Russian Foreign Minister Sergei Lavrov had a "productive call" but opted against an in-person meeting.

Trump had announced last week that he and Putin would meet soon in Hungary to try to bring an end to the conflict in Ukraine. However, Putin has been unwilling to consider concessions. Moscow has long demanded that Ukraine agree to cede more territory before any ceasefire.

Trump, asked by reporters about the prospect for a summit, said he did not want to have a "wasted meeting" but suggested there could be more developments and that "we'll be notifying you over the next two days" about them.

The Kremlin said on Tuesday it was unclear when a summit between Trump and Putin would take place, and that no dates had been mentioned by anyone.

"Listen, we have an understanding of the presidents, but we cannot postpone what has not been finalized, "Kremlin spokesman Dmitry Peskov said. "Neither President Trump nor President Putin gave exact dates."

Asked if Moscow had an understanding of a possible date for the summit, Peskov said, "No, there is no understanding."

Russia reiterated its long-standing terms for a peace deal in a private communique known as a "non paper" that it sent to the US on the weekend, according to two US officials and two people familiar with the situation.

The communique reaffirmed Russia's demand for full control of the eastern Donbas region, according to one official, effectively rejecting Trump's call for a ceasefire to commence with a freeze of the front lines at their prevailing locations, which was backed by Ukrainian President Volodymyr Zelensky.

Trump "proposed 'Stay where we stay and begin conversation'", Zelensky told reporters on Wednesday during a brief visit to Oslo. "I think that was a good compromise, but I'm not sure that Putin will support it, and I said it to the president."

European leaders urged Washington on Tuesday to hold firm in demanding an immediate ceasefire in Ukraine, with the present battle lines to serve as the basis for any future talks.

NATO said Secretary-General Mark Rutte traveled to Washington on Tuesday for talks with Trump that two sources familiar with the matter said would take place on Wednesday.

A Western official, speaking on condition of anonymity, said Rutte planned to present to Trump the European views on a ceasefire and any subsequent peace negotiations.

European Union leaders are then set to close ranks in support of Ukraine at a Brussels summit on Thursday, followed a day later by a "coalition of the willing" meeting of European leaders in London to discuss the next steps to help Kyiv.

Agencies Via Xinhua