President Barack Obama said Monday that Russia is "on the wrong side of history" and in violation of international law for sending troops into the Ukranian region of Crimea. He also promised America will make Russia face consequences for its actions.

Before a bilateral meeting with Israeli Prime Minister Benjamin Netanyahu at the White House, Obama told reporters the United States is considering economic and diplomatic options to "isolate" Russia and the government of President Vladimir Putin.

Obama noted the "world is largely united" in thinking Russia is in violation of international law. At home, Obama said Congress should immediately consider an aid package to Ukraine.

"So there are really two paths that Russia can take at this point," he said. "Obviously the facts on the ground in Crimea are deeply troubling, and Russia has a large Army that borders Ukraine. But what is also true is that over time this will be a costly proposition for Russia, and now is the time for them to consider whether they can serve their interests in a way that resorts to diplomacy as opposed to force."

The United Nations Security Council has called an emergency meeting Monday afternoon on the Ukrainian crisis.

Meanwhile, Russia's Black Sea Fleet has reportedly given Ukrainian forces in Crimea an ultimatum to surrender by midnight ET on Tuesday or face a military assault. The State Department said Monday that if the reports are true, it would amount to a "dangerous escalation" for which the U.S. would hold Russia directly responsible.



"What we are also indicating to the Russians is if in fact they continue on the current trajectory they’re on, then we are examining a whole series of steps — economic, diplomatic— that will isolate Russia and will have a negative impact on Russia’s economy and status in the world," Obama said.