A close collaborator of Russian President Vladimir Putin taunted President Barack Obama Monday via Twitter, after the U.S. administration imposed sanctions on Moscow for occupying Crimea and intervening in Ukraine's political affairs.

Western nations do not recognize the referendum because the polls were “administered under threats of violence and intimidation from a Russian military intervention that violates international law,” according to a White House statement.

After the Sunday referendum in Ukraine’s autonomous region of Crimea, which resulted in a 97 percent vote favoring secession from Ukraine and joining Russia, the U.S and Europe moved to impose sanctions on senior Russian political and military figures. One of them was deputy prime minister Dmitry Rogozin, who is also  the head of Russia's Military Industrial Commission and his government's Special Representative on anti-missile defence and negotiations with NATO countries on this issue.

Here is his tweet:


The reference is to sanctions freezing the assets held abroad by top Russian figures.

Rogozin, 50, is not new to incendiary comments. In November, before Moldova, an ex-Soviet republic, signed a trade agreement with Europe, Rogozin threatened the country when he made a reference to Russian natural gas exports. "Energy is important, the cold season is near, winter on its way,” he said, as quoted by several news agencies. “We hope that you will not freeze this winter.”

More recently, Rogozin said that any actions taken to “hinder the communications of Transnistria [a territory within Moldova’s borders inhabited by a majority of ethnic Russians] with the rest of the world will be a direct threat to the security and constitutional freedom of 200,000 citizens of Russia permanently living in Transnistria,” he tweeted, as reported by Interfax. He added that Russia will never forget that “it is the guarantor of constitutional rights of its citizens.”