WASHINGTON, D.C. -- Call it the Putin problem.
The Russian president is sending 16,000 additional soldiers into Ukraine, and he doesn't seem to care what the rest of the world has to say.
The Russians now surround Ukranian army bases, but the Ukraines inside don't seem to be preparing to fight.
U.S. Ambassador to the United nations, Samantha Powers, told the General Assembly, "What is happening today is a dangerous military intervention in Ukraine. It is an act of aggression. It must stop."
President Obama, meanwhile, repeated his warning.
"What cannot be done is for Russia with impunity to put its soldiers on the ground and violate basic principles that are recognized around the world," Obama said.
The U.S. is threatening sanctions against Russia. They include canceling trade talks, as well as this summer's G-8 summit in Sochi. Other sanctions include ultimately blocking Russia from international banking.
Illinois U.S. Senator Dick Durbin, in Chicago today, called Putin, "a thug."
"But remember," said Durbin, "he just finished the Sochi Olympics, where he was just trying to convince the world that Russia was this new, modern civilization and he destroyed it in the Crimea within hours and so we have to let him know that the Russians are not going to benefit from the Sochi Olympics or the new image they're trying to project when they act like the thugs that we've seen in the past."