Obama puts Ukraine violence squarely on Russia

President Barack Obama suggested Thursday that the U.S. might impose new economic sanctions on Russia, blaming it squarely for the warfare in eastern Ukraine. But he ruled out any military options and proposed no shift in an American-led strategy that has yet to convince Moscow to halt operations against its far weaker neighbor.

Briefing reporters at the White House, Obama said he spoke by telephone with Chancellor Angela Merkel of Germany, Europe's largest economy and a country that has led diplomatic efforts to end the fighting between Ukraine and Russian-backed rebels. They spoke after two columns of Russian tanks and military vehicles entered the country's southeast and fired Grad missiles at a border post and 1,000 Russian troops poured into the country, according to NATO and Ukrainian officials.

"We agree, if there was ever any doubt, that Russia is responsible for the violence in eastern Ukraine. The violence is encouraged by Russia. The separatists are trained by Russia, they are armed by Russia, they are funded by Russia," Obama said. "Russia has deliberately and repeatedly violated the sovereignty and territorial integrity of Ukraine, and the new images of Russian forces inside Ukraine make that plain for the world to see."

Obama was cautious in foreshadowing a possible American response, expressly ruling out any U.S. military involvement. He said Russia's recent activity in Ukraine would incur "more costs and consequences," though these seemed to be limited to economic pressure that will be discussed when Obama meets with European leaders at a NATO summit in Wales next week. He also offered "unwavering commitment" to Ukraine and announced that its Western-looking president, Petro Poroshenko, would visit the White House next month.

The Russian offensive comes after months of fighting in eastern Ukraine, which U.S. and other Western countries say Moscow has orchestrated. After Ukraine's pro-Russian leader fled the country earlier this year and a new government turned away from Moscow toward its European neighbors, Russia seized and annexed the Crimean Peninsula. Since then, it has continued to provide support for armed pro-Russian groups fighting the Ukrainian government despite rising U.S. and European sanctions against Russian government officials, banks and energy companies.

Obama said the sanctions have been "effective," prompting capital to flee Russia and its economy to decline, but they've done little to convince Putin to end Russia's intervention in Ukraine, a former Soviet republic. The president said Russia has been involved in all separatist activity and that the latest its latest escalation appeared to be a response to progress by Ukraine's government against the main rebel-held areas of Donetsk and Luhansk.

"This is not a homegrown, indigenous uprising in eastern Ukraine," Obama said. Putin, he added, has "repeatedly passed by potential off-ramps to resolve this diplomatically" and "we have not seen any meaningful action on the part of Russia to actually try to resolve this in diplomatic fashion."

Russia continued Thursday to say there is no proof its troops are operating in Ukraine, without delivering firm denials, even as its forces and separatist rebels appeared to take control of the strategic town of Novoazovsk, breaking open a third front in the war. The new southeastern front raises fears Moscow is creating a land link between Crimea and Russia. Novoazovsk lies on the road between the territories.

State Department spokeswoman Jen Psaki said Russia was engaged in a "pattern of escalating aggression." But she, too, was vague about any immediate steps the United States might take even to help Ukraine, saying Washington's focus was on "nonlethal" assistance and not any defensive or offensive military equipment.

Obama still held out hope for Russia to change course.

"What we're doing is to mobilize the international community to apply pressure on Russia," he said. "But I think it is very important to recognize that a military solution to this problem is not going to be forthcoming." Russia's actions have only hurt itself, he said, leaving it more isolated than at any point since the end of the Cold War - something he hoped would become increasingly apparent to its leaders.