The White House says US President Joe Biden called on his Russian counterpart Vladimir Putin to "de-escalate tensions" over Ukraine during a telephone exchange.
It comes amid a military buildup near Ukraine's border.
Moscow later confirmed Biden had made a proposal to hold a summit on the matter, without saying if it had been accepted.
According to a White House readout of the conversation, Biden pressed Putin on Russia’s military buildup, saying that he “emphasised the United States’ unwavering commitment to Ukraine’s sovereignty and territorial integrity”.
Ukraine and its Western allies are accusing Russia of massing tens of thousands of troops on the borders of the former Soviet republic, which has ambitions to join NATO.
Ukraine estimates more than 80,000 Russian troops have been deployed.
Moscow insists it is responding to a NATO military build-up near Russian borders. The country's defence minister, Sergei Shoigu, said the troop build-up "in response to the alliance's military activities that threaten Russia".
The presidential phone call came hours after Ukraine's foreign minister, Dmytro Kuleba, was courting support from top officials of NATO nations in Brussels. He also discussed the crisis with NATO's secretary-general Jens Stoltenberg, who issued a stark warning to Moscow.
"Russia's considerable military build-up is unjustified, unexplained and deeply concerning. Russia must end this military build-up in and around Ukraine, stop its provocations and de-escalate immediately," Stoltenberg said on Tuesday at a joint press conference with Kuleba.
Amid the recent tensions, the US has also notified Turkey that two US warships will sail to the Black Sea on April 14 and April 15 and stay there until May 4 and May 5. The US Navy ships have made regular visits to the Black Sea in past years, vexing Moscow.
Russian Deputy Foreign Minister Sergei Ryabkov denounced the latest deployment as “openly provocative,” adding: “American ships have absolutely nothing to do near our shores.”
“They are testing our strength and playing on our nerves,” Ryabkov said in remarks carried by Russian news agencies. “Seeing itself as the Queen of the Seas, the US should realize that the risks of various incidents are very high. We warn the US that it should stay away from Crimea and our Black Sea coast for its own benefit.”
The Kremlin said on Wednesday it would "study" the summit proposal made by U.S. President Joe Biden ahead of a meeting with Vladimir Putin.
Russian presidential spokesman Dmitry Peskov told reporters: ”It is still premature to talk about this meeting in a concrete way. It is a new proposal that will be studied."
He described the two presidents' conversation as "professional" and as having lasted "quite a long time".
Relations between Moscow and Washington have rapidly deteriorated since Biden became president in January.
At the same time, violence resumed at the beginning of the year in eastern Ukraine between Kyiv forces and pro-Russian separatists.
While Russia claims it is not a party to the conflict in east Ukraine, separatists are widely considered to be a Moscow proxy.
Euronews journalists recently visited Mayorsk, where Ukrainian soldiers reported an increase in fighting and the deaths of four people from their army nearby in shelling a week ago.
Ukraine's president, Volodymyr Zelenskyy, says 26 Ukrainian soldiers have died this year.
Ukraine has accused Russia of massing more than 80,000 troops near its eastern border and in Crimea, which Moscow annexed in 2014.