President Joe Biden and Russian President Vladimir Putin engaged in a two-hour video call on Tuesday.
The White House says Biden expressed "deep concerns" about the buildup of Russian forces along its border with Ukraine.
Biden reportedly made it clear that the U.S. and its allies "would respond with strong economic and other measures in the event of military escalation."
Biden called for de-escalation and a return to diplomacy, according to a readout of the call, which was provided by the White House.
"The presidents also discussed the U.S.-Russia dialogue on Strategic Stability, a separate dialogue on ransomware, as well as joint work on regional issues such as Iran," the readout says.
Following the call with Putin, Biden briefed European leaders.
"The leaders underscored their support for Ukraine’s sovereignty and territorial integrity, as well as the need for Russia to reduce tensions and engage in diplomacy," the White House said.