Russian President Vladimir Putin has sent a Christmas message to his US counterpart Barack Obama and called for bilateral cooperation in international challenges.

"The outgoing year confirmed that Russia-US relations are a key factor of ensuring international security," the Kremlin press service reported on Wednesday.

In the message, Putin also expressed confidence that Moscow and Washington could �effectively� react to threats and challenges and deal with crises all over the world through �building constructive dialogue and cooperation with account for mutual interests."

Last year, the Ukrainian crisis and the reunion of Crimea with Russia plunged Kremlin�s relations with Washington and its Western allies to their lowest point since the Cold War. Both countries are also at loggerheads over the conflict in Syria.

The Russian president also sent greetings to other world leaders, including British Prime Minister David Cameron, German Chancellor Angela Merkel, and French President Francois Hollande

By Press TV