NATO has accused Russia of sending more troops for a massive military buildup around Ukraine, although Moscow has said it is withdrawing troops and is open to diplomacy, Reuters reported.

At the start of two days of talks between NATO defense ministers, NATO Secretary-General Jens Stoltenberg, said," We have not seen any withdrawal of Russian forces. And of course, that contradicts the message of diplomatic efforts," Stoltenberg said. "What we see is that they have increased the number of troops and more troops are on their way."

Stoltenberg warned that the Russians often redeployed military equipment and troops during the buildup.

NATO will consider new steps to contain Russia on its eastern flank.

Allies are also likely to provide additional troops and equipment to NATO members in Eastern Europe. Diplomats said 4,000 new troops could be deployed in Romania, Bulgaria, Hungary and Slovakia. The ministers will also consider nuclear deterrence, although discussions are strictly confidential.

"The escalation of Russian troops at the Ukrainian border is increasing and significant, and implores us as an alliance to continue to work together," Canada's Defence Minister Anita Anand said as she arrived for the meeting.