Ukraine referendum
Germany & France see fresh momentum from Ukraine ceasefire
Officials said Ukraine had agreed to abide by a new seven-day truce proposed by Russian separatists.
One serviceman from Ukraine's government forces had been killed and three others wounded.
A truce to end fighting appeared stillborn last week after rebels ignored it.
Relations between the two have deteriorated since the overthrow of a Moscow-backed president.
The past four days have seen the rebels stage elections for leadership which the government called illegal.
Sergei Lavrov said the pending vote would be important from the point of view of legitimising power.
Female fighters on both sides said the men in their units treat them as equals.
The incident involved Vitaly Zhuravsky, a former member of ousted President Viktor Yanukovich’s party.
Petro Poroshenko told a televised meeting of the government a ceasefire was proving difficult to maintain.
The Ukrainian military’s press centre listed overnight rebel violations of the ceasefire accord in five sites.
A shift in Vladimir Putin's language on the conflict in eastern Ukraine reflects a transformation.
Three-way talks involving pro-Moscow rebels aim to pave the way for a new ceasefire.
The announcement came after a four-way phone call with Vladimir Putin and German and French leaders.
The suggestion is viewed as necessary to prevent militants and arms entering Ukraine.
A statement said Russia and Ukraine leaders discussed a possible ceasefire in eastern Ukraine.
The port city of Mariupol was reclaimed by govt forces in heavy fighting on Friday.
Kiev said it had reached a mutual understanding with Moscow on parts of a plan for ending violence.
The US president met Petro Poroshenko for the first time since his election last month.
The Ukrainian army rolled out an offensive against pro-Russia separatists holding the city of Slaviansk.