President Obama on Thursday sidestepped the question of whether Russia has mounted an invasion of Ukraine, describing the movement of troops and equipment across the border as an "incursion" and "continuation of what's been taking place" in the region.
Obama accused Russia of "deliberately and repeatedly" violating the sovereignty and territorial integrity of Ukraine, and vowed "more costs and consequences" from the United States and its allies.
More than 1,000 Russian troops have entered the country, and two columns of tanks and military vehicles have crossed the border, Ukranian and NATO officials told The Associated Press. Russia has also reportedly fired missiles from across the border to clear a pathway for the convoy. Reports also said Russian forces had taken control of a key Ukrainian town.
The president announced plans to meet with Ukrainian President Petro Poroshenko at the White House in the next month, and said the crisis in Ukraine would be a point of discussion at next week's NATO summit in Wales. Obama spoke with German Chancellor Angela Merkel before his statement to reporters Thursday afternoon.
Republican lawmakers, including House Armed Services Committee Chairman Buck McKeon (R-Calif.), have asked Obama to say definitively whether he considered Russia's actions in Ukraine an invasion.
"If reports prove accurate that Putin has in fact sent over 1,000 troops into Ukraine to support and fight alongside Russian-backed separatists, this is an act of war against the sovereign state of Ukraine," McKeon and Rep. Michael Turner (R-Ohio) said in a joint statement.
The government in Kiev has said it viewed the Russian activity as an invasion.
"What we registered is a direct invasion of the Russian military into the eastern regions of Ukraine," said Ihor Prokopchuk, Ukraine's envoy to the Organization for Security and Cooperation in Europe, according to NBC News.