Sergei Chuzavkov, Associated Press
Volunteers line up to take an oath of allegiance to Ukraine, before they were sent to the eastern part of Ukraine to join the ranks of special battalion "Azov", during a ceremony to take the oath of allegiance to Ukraine, in Kiev, Ukraine, Monday, June 23, 2014.

DONETSK, Ukraine — A former Ukrainian president led talks Monday to help end the fighting in eastern Ukraine, bringing together the Russian ambassador, pro-Russian rebel leaders and European officials.

The negotiations were launched in line with Ukrainian President Petro Poroshenko's peace plan, which started with a unilateral cease-fire Friday to uproot the mutiny that has engulfed the nation's industrial east.

Ukraine and the West have accused Russia of fomenting the rebellion in the east by sending troops and weapons across the border, but Moscow has denied that and insisted that Russian citizens who joined the insurgents were volunteers.

Russia has welcomed the peace plan but urged the Ukrainian government to engage in talks with the insurgents, who have seized official buildings, declared independence and fought government troops over the past two months. Hundreds of people have been killed and tens of thousands have fled their homes.

Poroshenko has ruled out talks with those he calls "terrorists," so inviting former President Leonid Kuchma to mediate offered a way to conduct talks without the government's formal engagement.

Kuchma, who served as president from 1994-2005, comes from the east and is an astute political player respected by both sides. His ex-chief of staff, Viktor Medvedchuk, has lived in Russia and reportedly has close ties to Russian President Vladimir Putin, was also in eastern Ukraine to help broker the talks.

Putin publicly expressed support Sunday for Ukraine's declaration of a cease-fire and urged both sides to negotiate a compromise, which must guarantee the rights of the Russian-speaking residents of eastern Ukraine.

Putin clearly intends to maintain pressure on the Ukrainian government in Kiev to give the country's eastern industrial regions more powers, which would allow them to keep close ties with Russia and serve the Kremlin's main goal of preventing Ukraine from joining NATO.

But the Russian leader also wants to avoid more crippling sanctions from the U.S. and particularly from the European Union, whose leaders will meet Friday in Brussels, and therefore needs to be seen as cooperating with efforts to de-escalate the conflict.

It's not clear if the separatists, who have asked to join Russia, will accept the cease-fire. Putin so far has rebuffed their requests.