MOSCOW (CBSDC/AP) — A senior Russian diplomat says Moscow may change its stance in the Iranian nuclear talks amid tensions with the West.

Deputy Foreign Minister Sergei Ryabkov was quoted Wednesday as saying by the Interfax news agency that Russia didn’t want to use the Iranian nuclear talks to “raise stakes,” but may have to do so in response to the actions by the United States and the European Union.

The statement is the most serious threat of retaliation by Moscow after the U.S. and the EU announced sanctions against Russia over the Ukrainian crisis.

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Speaking in Poland on Tuesday, Vice President Joe Biden warned Russia that even more sanctions could be coming.

“The world has seen through and rejected the flawed logic behind those actions,” Biden said as Russia moves forward on annexing Crimea. Biden added that what Russia is doing is “nothing more than a land grab.”

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