Germany's foreign minister said should the Crimea independence referendum be followed by steps to absorb the region into Russia, the EU will be forced to consider a further, third stage of sanctions.
Frank-Walter Steinmeier told reporters that Russia had so far rebuffed all European proposals to defuse the standoff in the Crimea region of Ukraine.
He said European states over the weekend would draw up a list of Russians who will be subject to visa restrictions and asset freezes as part of initial sanctions already agreed within the EU.
Barack Obama warned Russia that the West will be forced to apply a cost to Moscow if it fails to change course in its dispute with Ukraine.
The ballot paper that the people of Crimea will use in Sunday's referendum was published today
Vitali Klitschko's visit to the eastern city of Donetsk is clearly an attempt to try to ease the divisions with Ukraine.