Moscow: Russia said on Tuesday it hoped that talks on the status of eastern Ukraine would start shortly between Kiev and pro-Moscow rebels.
"We are hoping that the talks will start quickly," Russian foreign minister Sergei Lavrov told reporters, also urging Ukraine to conduct constitutional reforms.
"Fulfilling agreements is one of key conditions for a sustainable settlement of any conflict."
Kiev and separatist representatives on Friday inked a 12-point plan in Minsk mapping out a roadmap to resolving five months of brutal conflict but the truce has already been shaken by sporadic shelling on the ground.
The deal avoids calling for Ukraine to be turned into a federation but offers rebel regions "temporary special status". Kiev has until now refused to grant legitimacy to separatists, calling them "terrorists."
Russia`s top diplomat said that on the whole the ceasefire was holding but added that Russia was "seriously concerned" about Monday`s reports that Ukrainian forces were concentrating heavy weaponry near Debaltseve, some 70 kilometres to the northeast of Donetsk.
"One can make a conclusion that some sort of attack force is being put together," Lavrov said, adding that Kiev authorities sought to allay Moscow`s fears, saying it did not plan an attack on rebels.
"We will carefully monitor the situation," Lavrov added.
"We are not interested in anyone or anything trying to scuttle the implementation of the Minsk agreements."
The Ukrainian National Security and Defence Council said on Tuesday that Ukrainian forces in Debaltseve were being shot at by rebels.
The Defence Ministry said that four soldiers have been killed and 29 wounded since the ceasefire went into effect on Friday.