The White House joined Kiev tonight in accusing Russia of a "flagrant violation of international law" after a convoy of lorries carrying humanitarian aid crossed the border with Ukraine without permission.
It said Russia should remove them immediately, or face further economic sanctions.
ITV News' Europe Editor James Mates reports from Washington:
More top news
Find out what to expect from the weather if you are running in the big race in London or watching from the sidelines.
It will be a soggy start to the weekend and temperatures will drop making it feel colder than in recent days.
A British couple with a combined age of 194 are to become the world's oldest newlyweds when they marry in the summer.