The United States has warned Russia against any move to annex Crimea, saying that any action would close the door to diplomacy.
Secretary of State John Kerry told Russian counterpart Sergei Lavrov that Crimea is part of Ukraine and Moscow should avoid military escalation.
According to the BBC, Kerry made the comments during a telephonic conversation with Lavrov came in a telephone conversation on Saturday.
A State Department official said Kerry made clear that continued military escalation and provocation in Crimea or elsewhere in Ukraine, along with steps to annex Crimea to Russia would close any available space for diplomacy, urging utmost restraint.
Russian President Vladimir Putin has insisted he has the right to protect Russian interests and the rights of ethnic Russians in Crimea, the report added.