Top US and Russian diplomats will meet in Saudi Arabia on Tuesday for talks on resetting their countries' fractured relations and making a tentative start on trying to end the Ukraine war.

Both sides played down the chances that the first high-level meeting between the countries since US President Donald Trump took office would result in a breakthrough.

Still, the very fact the talks were taking place has triggered concern in Ukraine and Europe following the United States' recent overtures towards the Kremlin.

Ukrainian President Volodymyr Zelensky said Kyiv was not invited to the discussions in Riyadh, while European leaders were gathering in Paris for emergency talks on how to respond to the radical pivot by the new US administration.

Preparations for a possible summit between presidents Trump and Vladimir Putin are also expected to be on the agenda.

Trump is pushing for a swift resolution to the three-year conflict in Ukraine, while Russia sees his outreach as a chance to win concessions.

Zelensky said Kyiv "did not know anything about" the talks in Riyadh, according to Ukrainian news agencies, and that it "cannot recognize any things or any agreements about us without us".

He said on social media that any peace deal would need to include "robust and reliable" security guarantees, which France and Britain have called for but not all European powers support.

Russia said ahead of the meeting that Putin and Trump wanted to move on from "abnormal relations" and that it saw no place for Europeans to be at any negotiating table.

Russia's Foreign Minister Sergei Lavrov and senior Putin aide Yuri Ushakov will meet with US Secretary of State Marco Rubio, National Security Advisor Mike Waltz and Middle East envoy Steve Witkoff.

Possible Trump-Putin summit

Kremlin spokesman Dmitry Peskov told reporters the talks would be "primarily devoted to restoring the whole complex of Russian-American relations", alongside discussions on "possible negotiations on a Ukrainian resolution, and organizing a meeting between the two presidents".

Moscow, which for years has sought to roll back NATO's presence in Europe, has made clear it wants to hold bilateral talks with the United States on a plethora of broad security issues, not just a possible Ukraine ceasefire.

Before invading in February 2022, Putin was demanding the military alliance pull its troops, equipment and bases out of several eastern members that were under Moscow's sphere of influence during the Cold War.

The prospects of any talks leading to an agreement to halt the Ukraine fighting are unclear.

Both Russia and the United States have cast the meeting as the beginning of a potentially lengthy process.

"I don't think that people should view this as something that is about details or moving forward in some kind of a negotiation," US State Department spokesperson Tammy Bruce said.

Russia's Ushakov told state media the talks would discuss "how to start negotiations on Ukraine."

Both Ukraine and Russia have ruled out territorial concessions and Putin last year demanded Kyiv withdraw its troops from even more territory.

Zelensky will travel to Turkey on Tuesday to discuss the conflict with President Recep Tayyip Erdogan, and then Saudi Arabia a day later.

He does not plan to hold talks with either the US or Russian delegations, his spokesman said Monday.

Zelensky said last week he was prepared to meet Putin, but only after Kyiv and its allies had a common position on ending the war.

Saudi back in the fold

As European leaders gathered in Paris for an emergency security summit, Russia's Lavrov said Monday he saw no point in them taking part in any Ukraine talks.

The significance of the talks taking place in Riyadh was not lost on analysts.

A diplomatic pariah under the former US administration, it has been brought back into the fold with Trump's return.

"Europe's the traditional meeting place for the Americans and the Russians, but that's not an option in the current environment," said James Dorsey of the National University of Singapore. 

"You either go to Asia or you go to Saudi Arabia," he said.

Moscow heads into the talks boosted by recent gains on the battlefield, while Kyiv also faces the prospect of losing vital US military aid, long criticized by Trump.

by Leon Bruneau and Haitham El-Tabei