BERLIN, Sept. 3 (Xinhua) -- Germany urged Russia to keep engaging in diplomatic talks to resolve the Ukrainian crisis on Monday following the assassination of a pro-Russian rebel leader in eastern Ukraine.

"We urge all parties to continue with their constructive participation in negotiations," Steffen Seibert, spokesperson for German Chancellor Angela Merkel, told reporters in Berlin.

"It is really important that an escalation is prevented now," Seibert noted.

The remarks were made after Russian Foreign Minister Sergey Lavrov said Saturday the murder of Alexander Zakharchenko, leader of Ukraine's independence-seeking Donetsk region, made it impossible for the four-way Ukraine talks involving Russia, Ukraine, France and Germany, known as the Normandy format, to continue.

Zakharchenko was killed in an explosion at a cafe in Donetsk, part of Ukraine's Donbas region.

"This is a blatant provocation aimed at hindering the implementation of the Minsk agreements," Lavrov added.

The Minsk agreements resulted from the four-way talks includes a first protocol that the Ukrainian government and the rebels reached under the mediation of Russia, France and Germany in September 2014 in the Belarussian capital of Minsk, and a more detailed renewal of the agreement was signed in February 2015.

The Minsk agreements envisage a cease-fire, a withdrawal of heavy weaponry from the contact line, a prisoner exchange, and holding local elections in Donbas, among other measures.

Germany said the death of Zakharchenko should not invalidate the Minsk agreements.

Chancellor Merkel is scheduled to meet with French President Emmanuel Macron in Marseille on Friday. During the meeting, she is widely expected to raise the issue which could become a formidable threat to an already fragile peace in eastern Ukraine.

Zakharchenko, 42, was elected in November 2014 during the so-called regional "presidential elections," which were held in the insurgent-controlled areas in Ukraine's Donetsk and Lugansk regions, together known as Donbas, amid harsh criticism from Kiev.

Since April 2014, the insurgents in eastern Ukraine have been involved in an armed confrontation with Ukrainian government troops. The fighting has killed more than 10,000 people so far.

The Minsk agreements have never been fully implemented, with Kiev and the insurgents accusing each other of violation.