Obama: 'G7 ready to impose additional costs'

US President Barack Obama has warned Russia that the G7 nations are ready to impose additional sanctions over its actions in Ukraine.

The G7 summit is the first since Russia was expelled from the group, following its annexation of Crimea in March.

Although Russian President Vladimir Putin is not at the Brussels summit, he will hold face-to-face talks with some G7 leaders - not including President Obama - in Paris afterwards.