President Barack Obama Thursday stopped short of calling the Russian incursion in Ukraine an “invasion,” and said there would be no U.S. military intervention. He vowed to continue supporting Ukraine through diplomatic and financial assistance, however.

"It's is very important to recognize a military solution to this problem is not going to be forthcoming,” the president said during a news conference at the White Hosue. When asked by a reporter whether he would describe the escalating Ukraine crisis as an invasion by Russia, the president said, “I consider the actions that we've seen in the last week a continuation of what's been taking place for months now.”

“These separatists are backed, trained, armed, financed by Russia," he added. "Throughout this process we’ve seen deep Russian involvement in everything that they’ve done.”

“My expectation is we will take additional steps primarily because we have not seen any meaningful action on the part of Russia to try to resolve this in a diplomatic fashion,” he said, according to the New York Times. “The sanctions that we’ve already applied have been effective. Our intelligence shows the Russians know they’ve been effective.”

In contrast, the U.S. ambassador to the United Nations, Samantha Power, earlier in the day bluntly accused Russia of lying about its military intervention in Ukraine. In a blistering statement to the Security Council, she said “the mask is coming off” Russia’s actions, which she called “a threat to all of our peace and security.”

The president’s remarks came the same day that Ukraine reported Russian troops and tanks had crossed the border into Ukraine, a spokesman for Ukraine’s security council said. Obama is scheduled to discuss the Ukraine conflict with allies at a NATO summit next week.