Russian President Vladimir Putin (R) speaks with German Chancellor Angela Merkel as they attend a wreath-laying ceremony at the Tomb of the Unknown Soldier by the Kremlin walls in Moscow, Russia, May 10, 2015. (Xinhua/Reuters)

MOSCOW, April 17 (Xinhua) -- Russian President Vladimir Putin and German Chancellor Angela Merkel said in a telephone conversation they were ready to assist in political and diplomatic efforts on Syria, including the Geneva and Astana peace talks, the Kremlin said Tuesday.

Putin said that the recent action by a group of Western countries on Syria was "an act of aggression" that largely violated norms of international law and caused substantial damage to the prospect of a political settlement to the Syrian crisis, according to a Kremlin statement.

The United States, together with Britain and France, launched missile strikes on Syria's Douma on Saturday, claiming that they were in response to an alleged chemical weapons attack by the Syrian military. The Syrian government has categorically denied the accusation.

"Both sides (Putin and Merkel) expressed readiness to facilitate the resumption of political and diplomatic efforts on the Syrian issue, including at the Geneva and Astana platforms, and to continue bilateral contacts on this matter," the statement said.

The two leaders also stressed the importance of conducting "a thorough and objective investigation" of the mission of the Organization for the Prohibition of Chemical Weapons (OPCW) in Syria, it said.

On Monday, the British delegation to the OPCW accused Russia and Syria of barring the mission from entering Douma. Moscow denied the accusation by saying that OPCW experts were not given permission by the United Nations to visit Douma as a result of the missile strikes.