ANTALYA, Turkey - US Secretary of State John Kerry on Wednesday warned Russia that now was a critical time to implement a fragile peace deal to end the fighting in Ukraine, after his talks with President Vladimir Putin raised hopes of a slackening in tensions.

Kerry said there was an “enormous moment of opportunity” to bring to an end over a year of fighting in eastern Ukraine between government forces and pro-Russia separatists which has dragged relations between Moscow and the West to a new post-Cold War low.

Kerry, speaking at the NATO foreign ministers’ meeting in the southern Turkish city of Antalya hours after talking with Putin in Russia, said that the alliance was in “unanimity” on the importance of this year’s Minsk truce agreement being fulfilled by Moscow.

“I think there was strong agreement among all of the NATO members that this is a critical moment for action by Russia, by the separatists, to live up to the Minsk agreement.”

He added that it was also “critical” for observers from the Organization for Security and Cooperation in Europe (OSCE) to be allowed into the conflict areas to monitor the truce.

The intensity of the fighting in eastern Ukraine controlled by pro-Russia separatists has declined since the Minsk deal but deadly clashes remain frequent. (AFP)