In a highly anticipated video call on Tuesday, US President Joe Biden warned Russian President Vladimir Putin of "strong economic and other measures in the event of military escalation" in Ukraine, the White House said in a statement.
The two-hour meeting aimed to address rising tensions over Ukraine as Washington and Kyiv accuse Russia of planning an invasion.
Moscow has denied any aggressive intentions and accused the West of provocation, particularly with military exercises in the Black Sea.
US national security advisor Jake Sullivan said following the summit that Putin would "risk" Nord Stream 2 gas pipeline with a Ukraine invasion.
"President Biden voiced the deep concerns of the United States and our European Allies about Russia’s escalation of forces surrounding Ukraine," a White House statement read.
"President Biden reiterated his support for Ukraine’s sovereignty and territorial integrity and called for de-escalation and a return to diplomacy," it went on.
Putin demands 'guarantees' on NATO expansion
According to the readout released by the Kremlin after the talks, Putin demanded guarantees that ex-Soviet Ukraine would not join NATO in the future.
"Russia is seriously interested in obtaining reliable, legally fixed guarantees that rule out NATO expansion eastward and the deployment of offensive strike weapons systems in states adjacent to Russia," the Kremlin said.
Putin also demanded guarantees that offensive strike systems would not be deployed in countries neighbouring Russia, according to the Kremlin readout.
Biden gave no commitments to Putin on over any demand for Ukraine to be blocked from joining NATO or for a reduced US military presence in the region, Sullivan told reporters after the summit.
"I'm not going to... go into details in terms of what they discussed," US national security advisor Jake Sullivan said following Biden's virtual summit with Putin. "But I will tell you clearly and directly he made no such commitments or concessions."
Just hours before the call got underway, Ukrainian officials charged Russia was continuing to escalate the crisis by sending tanks and snipers to war-torn eastern Ukraine to "provoke return fire."
Ukraine’s Defense Ministry alleged that Russia is holding "training camps under the leadership of regular servicemen of the Russian Armed Forces." The Kremlin hasn’t commented on the allegations
Washington holds talks with NATO allies
Ahead of the talks, Biden consulted by phone with European allies on Monday evening about Russia's troop buildup on the Ukraine border, with a view to coordinate messaging and potential economic sanctions against Moscow.
He spoke again with them again on Tuesday following his call with Putin, Sullivan told reporters, and will talk to Ukraine's President Volodymyr Zelensky on Thursday.
Watch the full interview with Justyna Gotkowska, coordinator of the Regional Security Programme at the Centre for Eastern Studies, in the video player above.