Prorussian rebels
3 Ukrainian soldiers killed in past 24 hours
A military official said rebels had shelled Ukrainian positions 22 times over the past day.
The Ukrainian Defence Ministry said 13 servicemen were killed and 157 wounded during the withdrawal.
Over 5,000 lives have so far been claimed in the conflict.
Officials said rebels had carried out several small arms attacks on Ukrainian positions in the east.
Relations between the two have deteriorated since the overthrow of a Moscow-backed president.
Russia backs the separatists but denies it is directly involved in conflict in the Donbass region.
The Russian leader said the sanctions went against international law as only the UN had the right to do so.
Ukraine has accused Russia of sending soldiers and weapons to help separatist rebels in eastern Ukraine.
A military spokesperson suggested pro-Russian rebels were planning a new offensive.
The past four days have seen the rebels stage elections for leadership which the government called illegal.
Separatist leaders accused Petro Poroshenko of suspending a law giving their regions “special status”.
Sunday's vote took place in defiance of Kiev's pro-Western authorities.
NATO said in a statement its jets had intercepted four groups of Russian aircraft since Tuesday.
Sergei Lavrov said the pending vote would be important from the point of view of legitimising power.
City authorities blamed the shelling on rebels and separatists blamed it on government forces.
Patriarch Kirill was presented with a single-seater fighter jet SU-35.
Russia says weaponry from NATO states will abet war crimes in Ukraine and worsen the situation.
Petro Poroshenko told a televised meeting of the government a ceasefire was proving difficult to maintain.
Washington and Moscow have questioned each other’s commitment to the Intermediate-Range Nuclear Forces treaty.