NATO to oppose Russian aggression: Barack Obama tells Europe

Washington: Confronted by a Kremlin-backed military offensive in Ukraine, President Barack Obama and Western allies will approve plans this week to position at least 4,000 troops and military equipment in Eastern Europe, bolstering NATO's security commitments to nervous member states near the Russian border.

Ahead of a high-stakes NATO summit that begins tomorrow, Obama will also make a symbolic show of solidarity with Eastern Europe when he visits Estonia for meetings with Baltic leaders. He was due to arrive in the Estonian capital of Tallinn today morning.

Russia's months-long conflict with Ukraine comes at a time when members of the NATO defence alliance have been cutting military spending and reassessing the organisation's role after years of peace in Europe. While Ukraine is not part of NATO, alliance members in Eastern and Central Europe fear they could be Russia's next targets, prompting the 28-nation bloc to seek a more robust response.

"The current situation shows that the principle of collective territorial defence hasn't gone away — on the contrary," Estonian President Toomas Hendrik Ilves said Sunday, marking the 20th anniversary of the exit of the last Russian troops from Estonian territory.

Ukrainian officials say their country's armed forces are now locked in a conflict with not only Moscow-backed separatists, but also the Russian army. Officials said yesterday that Russian military forces had been spotted in two major rebel-held cities in eastern Ukraine, though that could not be independently verified.

Russian President Vladimir Putin has denied that his forces are invading Ukraine. A Kremlin aide sharply criticised EU Commission President Jose Manuel Barroso Tuesday, accusing him of breaching confidentiality when he quoted Putin as saying that Moscow could take over Kiev in two weeks if it wished.

Yuri Ushakov, the Russian leader's foreign policy adviser, told reporters that Putin's statement was "taken out of context and carried a completely different meaning." For Obama, Russia's provocations in Ukraine and his response to them have prompted criticism that he has been unable to stop the crisis through his preferred method of steadily escalating economic sanctions. The president has warned Putin that the U.S. And Europe could impose more financial penalties, but he remains steadfastly opposed to intervening militarily.