Peace talks in Ukraine collapsed Saturday amid fighting in Donetsk, a strategic town for both the Russia-backed rebels and government forces. 

Rebel leaders Alexander Zakharchenko and Igor Plotnitskiy did not attend the negotiations in Minsk, according to Bloomberg. The former Ukrainian President Leonid Kuchma said the self-declared leaders from the Donetsk and Luhansk republics refused to discuss a cease-fire and withdrawal of arms. Negotiations only lasted three hours. 

Donetsk rebels and separatists want the current Ukrainian president, Petro Poroshenko, to declare a truce before any new talks about peace can occur, said a negotiator for the Donetsk rebels Denis Pushilin.

The meeting in Minsk, the Belarusian capital, took place between Ukraine's representative Kuchma, Russia's ambassador to Ukraine Mikhail Zurabov, a representative of the Organization for Security and Cooperation in Europe, Heidi Tgliavini, and the separatists. The talks came about as a result of an escalation of violence in eastern Ukraine. The groups agreed on a cease-fire in September, but that has been ignored. 

Before the negotiations ended, German Chancellor Angela Merkel, French President Francois Hollande and Russia's President Vladmir Putin had a three-way phone call to express their hope that the meeting would produce another cease-fire agreement, according to Reuters.

The conflict in Ukraine erupted in April 2014 after Russia annexed Crimea in response to the ousting of a Moscow-backed president in Kiev by street protests. The conflict has claimed the lives of more than 5,000 people. 

This is the gravest crisis between Russia and the West since the Cold War with the U.S., Reuters reported. Both the U.S. and the European Union have imposed sanctions on Moscow because they claim to have proof that Russia is providing arms and men to the separatists. Moscow denies these claims.