NATO suspends cooperation with Moscow

Russian President Vladimir Putin told German Chancellor Angela Merkel Monday that he'd ordered a "partial withdrawal" of troops from his country's border area with Ukraine.

Earlier, Ukraine condemned a visit to Crimea by Russian Prime Minister Dmitry Medvedev and a delegation of government ministers.

Tensions between Russia and the West rose after the overthrow of pro-Kremlin Ukrainian President Viktor Yanukovych in February, following months of street protests.

Later, Russia's subsequent decision to annex Crimea triggered a crisis in relations.

Crimeans voted to leave Ukraine for Russia on March 16, in a referendum condemned as illegal by the UN General Assembly.

Concerns are high that Russia, which US officials last week said had about 40,000 troops near the frontier, might seek to enter Ukraine.