U.S. President Barack Obama and Russian President Vladimir Putin on Friday discussed the implementation of a plan to resolve the ongoing conflict in Ukraine, in a conversation that a senior U.S. official described as "constructive."
"They exchanged views on the need to implement quickly the political agreement reached today in [Kiev], the importance of stabilizing the economic situation and undertaking necessary reforms, and the need for all sides to refrain from further violence," the White House said in a statement.
An English-language statement on the Kremlin website described the conversation as "substantive" and said Putin had "stressed the need to take immediate measures to stabilize the conflict, emphasizing the importance of working with the radical opposition, which has taken the confrontation in Ukraine to a very dangerous point."
Washington has said that both sides in the conflict must refrain from violence but that it holds the government of Ukrainian President Viktor Yanukovych ultimately responsible for putting an end to the deadly clashes.
Yanukovych on Friday signed an agreement with opposition leaders, agreeing to an early presidential election and a return to a 2004 constitution designed to limit presidential powers and make the country a parliamentary republic.
In a call with reporters on Friday, a senior official at the U.S. State Department called the phone call between Putin and Obama "constructive" and said the two leaders said "the agreement reached needed to be implemented quickly."
"It's clearly an important signal that the [U.S.] President and President Putin were able to talk positively about implementing this agreement," the official said, the Washington newspaper The Hill reported on its website. "We have to move on from there and ensure that this very, very fragile Ukrainian economy is stabilized."
The United States and its EU partners have been at odds with Russia over the crisis in Ukraine, with officials in Moscow accusing the West of stoking the violence by backing what they describe as radical elements seeking to carry out a coup against Yanukovych.
European and U.S. officials however, argue they are merely supporting Ukrainians' right to protest peacefully.
As Obama and Putin were preparing to speak by phone, White House spokesman Jay Carney told reporters on Friday that "it is in Russia's interest for the violence to end in Ukraine, as it is in the interest of the United States and our European friends."
"We welcome the cessation of violence, and we welcome the agreements that have been reached," Carney said.
During the call, which the Kremlin says was initiated by Obama, the two leaders also discussed Iran's nuclear program and the situation in war-torn Syria.
Both sides said in their respective statements that Obama congratulated Putin on the Winter Olympics currently being held in Russia's Black Sea resort of Sochi.