As it happened: Ukraine crisis

Key Points

• Russia's parliament has approved a request from President Vladimir Putin to deploy Russian troops in Ukraine
• The unrecognised new prime minister of Ukraine's Crimea region asked Mr Putin for assistance to maintain peace
• Pro-Russian protests have been reported in Kharkiv, Donetsk and Odessa - some have led to violent clashes
• Leading Ukrainian politician Vitali Klitschko has urged parliament to debate national mobilisation
• Troops believed to be Russian have surrounded key installations in Crimea
• US President Barack Obama warned Moscow any military intervention would come at a cost to Russia
• All times GMT