Live updates from BBC:
http://www.bbc.com/news/world-europe-26645477
19:56:
Nato chief Anders Fogh Rasmussen calls the Crimea crisis "a wake-up call... for the Euro-Atlantic community. For Nato. And for all those committed to a Europe whole, free and at peace". He is in Washington to discuss Ukraine with US officials.
20:00:
Nato is concerned Russia may move into eastern Ukraine, Nato's Rasmussen says.