Obama warns of costs for Ukraine intervention

The US president has warned Russia military intervention in Ukraine would lead to costs as tensions rise.

The US president has warned Russia military intervention in Ukraine would lead to costs as tensions rise. Picture: AFP.

WASHINGTON - President Barack Obama warned Russia on Friday that military intervention in Ukraine would lead to "costs," as tension with old foe President Vladimir Putin rose in a Cold War-style crisis.

"We are now deeply concerned by reports of military movements taken by the Russian Federation inside of Ukraine," he told reporters.

Obama and European leaders would consider skipping a G8 summit this summer in the Russian city of Sochi if Moscow intervenes militarily in Ukraine, a senior US official said. The G8 includes the world's seven leading industrial nations and Russia.

"The United States will stand with the international community in affirming that there will be costs for any military intervention in Ukraine," Obama said in the White House briefing room.

Facing yet another confrontation with Putin after butting heads with him over Syria, Obama said any violation of Ukraine's sovereignty and territorial integrity would be "deeply destabilising."

Obama did not spell out what he meant by Russian military intervention.

Russia has a huge naval base in Ukraine's Crimea Peninsula and says it has the right to move troops in Ukraine under an agreement between the two former Soviet neighbours.

US officials said they saw indications of Russian troop movements into Crimea but that their numbers and intentions were unclear.

The chairman of the US House of Representatives Intelligence Committee, Republican Mike Rogers, said in a statement: "It appears that the Russian military now controls the Crimean peninsula."

Vice President Joe Biden called Ukrainian Prime Minister Arseny Yatseniuk on Friday "to reaffirm the United States' strong support for the new government and our commitment to the sovereignty, territorial integrity, and democratic future of Ukraine," the White House said.

The crisis has presented Obama with a difficult challenge days after the ouster of Viktor Yanukovich, Ukraine's pro-Moscow president, who fled to Russia following three months of protests in Kiev.

Parliament Speaker and newly-appointed interim president of Ukraine, Olexandr Turchynov speaks during a session at the Parliament in Kiev on 23 February, 2014. Picture: AFP.

Armed men took control of two airports in the Crimea region in what the new Ukrainian leadership described as an invasion by Moscow's forces, and Yanukovich surfaced in Russia a week after he fled Kiev.

Ukraine fell into political crisis last year when Yanukovich spurned a broad trade deal with the European Union and accepted a $15 billion Russian bailout that is now in question.

A US response to any Russian intervention in Ukraine could include avoiding deeper trade and commerce ties that Moscow is seeking, the senior US official said.

Steven Pifer, a former US ambassador to Ukraine now at the Brookings Institution think tank, said it was inconceivable that the United States would consider a military response were Russia to seek to gain control of Crimea, and that it had few plausible options to oppose such a move.

"If you look at the US-Russian relationship, what kinds of things could we do to punish them? There are not a lot of good levers there," he added.

Putin has proved immune to US calls for Moscow to stop supporting Syria's government in its three-year-old civil war. And the United States was unable to prevent Putin from staging Russian incursions into neighbouring Georgia in 2008.