A day of frantic activity following Crimea's vote Sunday to break away from Ukraine
The United States and European Union have imposed personal sanctions on Russian and Crimean officials involved in what they say was the seizure of Crimea from Ukraine.
While the West was doing this, Russian President Vladimir Putin signed a decree late Monday recognizing Crimea as a sovereign state.
The moves have heightened the most serious East-West crisis since the end of the Cold War.
The Crimean parliament has formally asked that Russia admit Crimea as a new subject with the status of a republic.
Putin will on Tuesday address a special joint session of Russia's parliament, which could take a decision on annexing of the region.
U.S. President Barack Obama imposed sanctions on 11 Russians and Ukrainians blamed for the seizure, including toppled Ukrainian President Viktor Yanukovich, and two aides to Putin.