NEW : Meanwhile , Ukrainian officials charged that pro-Russian forces comprised of 100 armed men reportedly took control of a military office in the Crimean regional capital , Simferopol . John Kerry tells Russia its continued escalation `` would close ... space for diplomacy '' Obama rounds up world leaders to demand Russia `` de-escalate '' crisis . Russian troops seized a Crimean border control point , Ukraine border service says . The U.S. and the European Union have imposed sanctions on Moscow over Crimea's move toward joining Europe.
NEW : John Kerry tells Russia its continued escalation `` would close ... space for diplomacy '' Obama rounds up world leaders to demand Russia `` de-escalate '' crisis . Russian troops seized a Crimean border control point , Ukraine border service says . The U.S. and the European Union have imposed sanctions on Moscow over Crimea's move toward joining Europe.