KIEV, Ukraine — Ignoring the toughest sanctions against Moscow since the end of the Cold War, Russian President Vladimir Putin recognized Ukraine's Crimean peninsula as an "independent and sovereign country" on Monday, a bold challenge to Washington that escalates one of Europe's worst security crises in years.
The brief decree posted on the Kremlin's website came just hours after the United States and the European Union announced asset freezes and other sanctions against Russian and Ukrainian officials involved in the Crimean crisis. President Barack Obama warned that more would come if Russia didn't stop interfering in Ukraine, and Putin's move clearly forces his hand.
The West has struggled to find leverage to force Moscow to back off in the Ukraine turmoil, of which Crimea is only a part, and analysts saw Monday's sanctions as mostly ineffectual.
Moscow showed no signs of flinching in the dispute that has roiled Ukraine since Russian troops took effective control of the strategic Black Sea peninsula last month and supported the Sunday referendum that overwhelmingly called for annexation by Russia. Recognizing Crimea as independent would be an interim step in absorbing the region.
Crimea had been part of Russia since the 18th century, until Soviet leader Nikita Khrushchev transferred it to Ukraine in 1954. Both Russians and Crimea's majority ethnic Russian population see annexation as correcting a historic insult.
Ukraine's turmoil — which began in November with a wave of protests against President Viktor Yanukovych and accelerated after he fled to Russia in late February — has become Europe's most severe security crisis in years.
Russia, like Yanukovych himself, characterizes his ouster as a coup, and alleges the new authorities are fascist-minded and likely to crack down on Ukraine's ethnic Russian population. Pro-Russia demonstrations have broken out in several cities in eastern Ukraine near the Russian border, where the Kremlin has been massing troops.
Fearing that Russia is prepared to risk violence to make a land-grab, the West has consistently spoken out against Russia's actions but has run into a wall of resistance from Moscow.
Reacting to Monday's sanctions, Russian Deputy Foreign Minister Sergei Ryabkov declared that they were "a reflection of a pathological unwillingness to acknowledge reality and a desire to impose on everyone one-sided and unbalanced approaches that absolutely ignore reality."
The White House imposed asset freezes on seven Russian officials, including Putin's close ally Valentina Matvienko, who is speaker of the upper house of Parliament, and Vladislav Surkov, one of Putin's top ideological aides. The Treasury Department also targeted Yanukovych, Crimean leader Sergei Aksyonov and two other top figures.
The EU's foreign ministers slapped travel bans and asset freezes against 21 officials from Russia and Ukraine.
"We need to show solidarity with Ukraine, and therefore Russia leaves us no choice," Polish Foreign Minister Radoslaw Sikorski said in Brussels.
On Monday Vice President Joe Biden was heading to Europe to meet with NATO allies.
In Kiev, acting President Oleksandr Turchynov vowed that Ukraine will not give up Crimea.