US President Barack Obama imposes more sanctions on Russia

President Barack Obama has said the US is moving to impose additional sanctions on individuals linked to Russia's annexation of Crimea.

Mr Obama said Russian threats to southern and eastern Ukraine posed a dangerous risk of escalating the crisis.

And he said he had signed an executive order giving him powers to impose sanctions on key sectors of the Russian economy.

The US president added this was not his preferred outcome, and that Russia could still de-escalate the crisis.