Russia yesterday rejected a new peace initiative for Ukraine as fears of open war mounted over the ex-Soviet republic, whose troops are waging an increasingly deadly offensive against pro-Moscow rebels.
Kiev announced the death toll from an assault on a rebel-held flashpoint town in the east had climbed over 34 yesterday.
"We are not very far from a military confrontation in Ukraine," said German Foreign Minister Frank-Walter Steinmeier in an interview to European newspapers.
The West, which is threatening to broaden sanctions on Russia over the worsening crisis, sees a May 25 presidential poll in Ukraine as crucial to hauling the country back from the brink.
The Swiss presidency chairing the Organisation for Security and Cooperation in Europe yesterday urged a suspension of hostilities for that election to take place.
Ukraine's foreign minister, Andriy Deshchytsia, appealed to 30 of his counterparts assembled in Vienna to help "eliminate the external threats and provocations supported by Russia" to ensure the election goes ahead.
But Russian Foreign Minister Sergei Lavrov, also at the Vienna meeting of the Council of Europe, said holding the vote during the current violence would be "unusual". President Vladimir Putin's spokesman has been more blunt, calling it "absurd".
The diplomatic impasse came as Ukraine spiralled into deeper violence.
Nearly 90 people have died in less than a week: half around the eastern town of Slavyansk, held by rebels since early April; and half in the southern port city of Odessa, where clashes culminated in a deadly inferno last Friday. Most killed have been pro-Russian fighters and activists.
Putin has so far held off ordering an invasion to "protect" Ukraine's Russian-speaking population, keeping an estimated 40,000 troops on the border for the past two months. And the Kremlin claims to be receiving "thousands" of calls for help from eastern Ukraine.
Kiev and its Western backers see Moscow's main aims as making sure Ukraine's east holds a planned "referendum" for independence on Sunday, and sabotaging all possibility of the nationwide presidential election two weeks later.
With those deadlines ticking closer, Ukraine's authorities are stepping up their offensive to crush rebels holed up in Slavyansk, a town of more than 110,000 people that is the epicentre of the insurgency.