Updated

NATO's chief says his top priority will be supporting French and German efforts to bring about a cease-fire in eastern Ukraine, but if a truce is negotiated it must be monitored so the Russian-backed separatists don't use it to regroup and rearm.

NATO Secretary-General Jens Stoltenberg told The Associated Press on Friday on the sidelines of the Munich Security Conference that the situation in Ukraine is "critical."

He says that's "why it's important to fully support this new initiative" by German Chancellor Angela Merkel and French President Francois Hollande, who met with leaders in Kiev before talking Friday with Russian President Vladimir Putin in Moscow.

If a truce is negotiated, he says "it is extremely important that we have effective systems of monitoring, of making sure the cease-fire is respected."