WASHINGTON, April 13 (Reuters) - The United States is prepared to step up sanctions against Russia if recent actions in Ukraine continue, U.S. Ambassador to the U.N. Samantha Power said on Sunday.
Pro-Russian activists on Saturday seized government buildings in the eastern town of Slaviansk, about 150 km (90 miles) from the Russian border. Ukrainian security forces on Sunday were trying to oust the activists, who set up barricades on the outskirts of the city.
Power said on ABC's "This Week" the latest events in Ukraine bore "the telltale signs of Moscow's involvement."
She said sanctions already imposed by Washington have had an impact: the Russian rouble has fallen to an all-time low, the Russian stock market has depreciated by 20 percent and investors are fleeing the country.
"The president has made clear that, depending on Russian behavior, that sectoral sanctions in energy, banking, mining could be on the table, and there's a lot in between," she said.
"I think we've seen that the sanctions can bite and if actions like the kind we've seen over the last few days continue, you're going to see a ramping up of those sanctions," Power said.
Ukraine faces a rash of rebellions in the east that it says are inspired and directed by the Kremlin.
NATO described the appearance in eastern Ukraine of men with specialized Russian weapons and identical uniforms without insignia - as previously worn by Moscow's troops when they seized Crimea - as a "grave development."
Power said the rebellion has "all the telltale signs of what we saw in Crimea: it's professional, it's coordinated, it's nothing grassroots-seeming about it. The forces are doing in each of the six or seven cities that they've been active in exactly the same thing." (Reporting by Doina Chiacu; Editing by Sandra Maler and Jim Loney)