President Barack Obama and Russian President Vladimir Putin "exchanged views" on the need to quickly implement the political agreement reached on Friday in Ukraine and for all sides to "refrain from further violence."
A White House statement said the two leaders spoke by phone and also discussed Syria, including the "importance of efforts to advance a political solution" to the civil war.
The conversation also covered concerns about the humanitarian crisis and the need for the regime of Syrian President Bashar al-Assad to "adhere to its commitment to eliminate" chemical weapons, the White House said.
Earlier, a senior State Department official described the conversation as "constructive" with both governments pledging to remain engaged in the Ukrainian situation.
The Kremlin also said in a statement the two had "a substantive" discussion on Ukraine and other issues.