Crystal clear that Russian army is in Ukraine, says PM Yatsenyuk

It is "crystal clear" that Russia has boots on the ground in Ukraine, the Ukrainian Prime Minister has said.

Speaking at a news conference with US Secretary of State John Kerry, Arseniy Yatsenyuk said he had strong evidence that President Putin had ordered Russian troops to invade Crimea and the east of Ukraine.

He said they were not fighting rebels or guerillas, they were fighting the regular Russian army.