The United States has suspended all military ties with Russia and is preparing possible sanctions on top Russian officials amid the ongoing crisis in Ukraine. Over the weekend, Russian troops seized parts of Ukraine’s Crimean Peninsula following the ouster of the pro-Russian President Viktor Yanukovych. Speaking earlier today, Russian President Vladimir Putin said Yanukovych is Ukraine’s only legitimate leader.

President Vladimir Putin: “The definition of what has happened in Kiev, and in Ukraine as a whole, the definition could be the only one: It is an unconstitutional coup and a military seizure of power. Nobody is arguing with that. Who is arguing with that?”

Ukraine’s ambassador to the United Nations said Russia had deployed 16,000 troops in the Crimean Peninsula and had called for Ukrainian forces to surrender. Putin said Russia would use military force only as a “last resort” in the event of “lawlessness” and would take action only to protect the Ukrainian people. On Monday, President Obama said the United States is considering a range of steps against Russia.

President Obama: “I think the strong condemnation that it’s received from countries around the world indicates the degree to which Russia is on the wrong side of history on this. We are strongly supportive of the interim Ukrainian government. John Kerry is going to be traveling to Kiev to indicate our support for the Ukrainian people, to offer very specific and concrete packages of economic aid, because one of the things we’re concerned about is stabilizing the economy, even in the midst of this crisis.”

Kerry is meeting with interim leaders in Ukraine today. Earlier today, the Ukrainian Parliament approved a deal to receive $839 million in loans from the European Union, while Russia’s state gas company, Gazprom, said it would cancel its discount for Ukraine.