Ukraine is just a few steps away from a war that "could destroy the security framework in Europe" and lead the world into a new Cold War, Germany's foreign minister said on Tuesday.
"The photographs that we have been receiving are horrifying and we are not very far from a military confrontation in Ukraine, especially after the tragedy in Odessa," said Foreign Minister Frank-Walter Steinmeier in an interview published in four European newspapers.
A blaze at a trade union building in Odessa on Friday left 42 people dead, mostly pro-Russian militants, after running battles with supporters of the new government in Kiev.
Steinmeier said a war in Ukraine "could destroy the security framework in Europe built over decades".
"That's why we must do everything possible to avert this risk and the start of a new Cold War," he told Spain's El Pais, France's Le Monde, Italian daily La Repubblica and Gazeta Wyborcza of Poland.
Germany has been pushing for a second international conference in Geneva despite the rapid collapse of the first agreement signed there in April.
Steinmeier said the first agreement had failed as it had not put in place "a mechanism that would translate what had been decided into reality."
The Geneva accord signed by Ukraine, Russia, the United States and the European Union called for all "illegal armed groups" in Ukraine to surrender their weapons and halt the occupation of public buildings and other sites.
Steinmeier said the proposed new conference would establish clear-cut steps to "achieve a de-escalation where tensions are particularly high."
It should also lead to an agreement on a presidential election due on May 25, which Russia says cannot be held under current conditions.
Russian Foreign Minister Sergei Lavrov on Tuesday said a second Geneva peace conference would achieve little if the first agreement remained unimplemented.
Amid spiralling violence in Ukraine, pro-Russian separatists are preparing their own independence referendum on Sunday, echoing a March vote in the mainly Russian-speaking province of Crimea that led to its annexation by Moscow.