The US envoy to UN warned on Wednesday that America is ready to impose sanctions on Russia over its "aggression" in Ukraine

The US envoy to UN warned on Wednesday that America is ready to impose sanctions on Russia over its "aggression" in Ukraine.

"A thief can steal property, but that does not confer the right of ownership on the thief," Samantha Power said in New York.

The United States also said on Wednesday that new sanctions to punish Moscow were ready.

"The question at this point is not if we will do more sanctions, it's when," State Department spokeswoman Jen Psaki told reporters.

However Russia's Deputy Foreign Minister Sergei Ryabkov warned Washington that Moscow was preparing a series of responsive or asymmetrical measures against United States.

The measures covered areas of dialogue, which are important to the Americans, Ryabkov said.

The talks over Iran's nuclear program could provide a means of response, he added

Crimea Releases Ukrainian Navy Chief

The Crimean authorities released the Ukrainian  navy chief that was seized during an attack on a base in the peninsula, the Ukrainian acting president said.

"Admiral Sergiy Gayduk was released tonight along with all the other civilian hostages... seized by Russian soldiers and members of the self-declared authorities of Crimea", Oleksandr Turchynov was quoted by the Interfax news agency.