council was meeting for the 24th time on Ukraine and the fighting between pro-Russia separatists and the new Ukrainian government.

"Every single one has sent a straightforward, unified message: 'Russia, stop this conflict. Russia is not listening,'" she said, adding that Russia's force along the border with Ukraine is the largest it's been since it started deploying there in late May.

Russia "has manipulated. It has obfuscated. It has outright lied," Power said. She said the U.S. will work with its G7 and European partners "to ratchet up the consequences on Russia." France also warned of increased sanctions if the escalation continues.

Russian Ambassador Vitaly Churkin offered a spirited defense, saying Kiev "is waging war against its own people."

Churkin did deny not the presence of Russian fighters.

"There are Russian volunteers ineastern parts of Ukraine. No one is hiding that," he said. But he questioned the presence of Western advisers in the country and asked where Ukrainian troops were getting weapons.

Churkin said he wanted to "send a message to Washington: Stop interfering in the internal affairs of sovereign states."

Moscow has been virtually isolated in the Security Council meetings on the Ukrainian crisis, but because of Russia's veto power as one of the council's five permanent members, the body has been unable to act.

Statements from NATO, Ukrainian President Petro Poroshenko, the separatists, the United States and the president of the Security Council on Thursday left no doubt that Russia had crossed the border into Ukraine. The various statements cited internal reports, satellite imagery of armored vehicles and even photographs from