G7 to reject Crimea poll result
The G7 group of world leaders have said they will not recognise the results of a referendum for the Crimea region to split from Ukraine and join Russia.
A statement from the seven nations released by the White House calls on Russia "to cease all efforts to change the status of Crimea contrary to Ukrainian law and in violation of international law".
It says the referendum scheduled for this weekend "would have no legal effect", and the process is deeply flawed.
The leaders said they would take further action, individually and collectively, if Russia tries to annex Crimea.
The statement was from the leaders of Britain, Canada, France, Germany, Italy, Japan and the United States, along with the European Council and the European Commission.
Meanwhile, Ukraine's new prime minister Arseniy Yatsenyuk is in Washington today for talks with US President Barack Obama at the White House.
Tomorrow, he will brief the UN Security Council in New York at an open meeting.
During the visit, he is expected to reiterate that Sunday's referendum in the Crimea is illegal.
Russia has become increasingly isolated in the Security Council, with even close ally China reaffirming Ukraine's territorial integrity. But Moscow can still block any council action using its veto power.