Tension and fears are mounting
And here are some other pieces that break down what is happening:
1 of 7
1 of 6
"We cannot and will not allow the integrity or the sovereignty of Ukraine to be violated" or let any such violation go without redress, U.S. Secretary of State John Kerry said moments ago in Paris, where he and other top diplomats met with Russia's foreign minister about Ukraine.
He said the United States is "ready to work with all parties" to resolve the crisis.
He said foreign ministers -- including those from Russia and Ukraine -- meeting today in Paris "agreed to continue intense discussions in the coming days."Kerry and Russian Foreign Minister Sergey Lavrov met three times today in the French capital. One of those meetings included a "brief and informal discussion" among Kerry, Lavrov, British Foreign Secretary William Hague, French Foreign Minister Laurent Fabius and German Foreign Minister Frank-Walter Steinmeier, an official said.
"It seems reflexes of the past prevailed and prevented an objective analysis of the situation. We think that attempts to add 'the NATO factor' to the already complicated and fragile situation in Ukraine are extremely dangerous, as it creates an additional element of tensions and undermines normalization prospects," Lukashevich said, answering a media question on the ministry website, according to Interfax.
Earlier this week, U.S. Defense Secretary Chuck Hagel announced measures to beef up the number of fighter jets in the former Soviet Baltic states of Lithuania, Latvia and Estonia, adding six F-15s to the four already participating in a NATO "air policing" mission in the region.