Pro-Russian separatists have not ceased their attacks on government positions, said Ukraine's military on Monday, so Ukraine cannot start retreating from the frontline in the east, according to Reuters.

Despite an agreement reached this weekend to start removing weapons from the frontline, rebels and Ukrainian military are finding it difficult to make the ceasefire stick. The ceasefire came into effect on Feb. 15, and though violence has been reduced, spokesman Anatoly Stelmakh said rebels attacked government troops twice overnight.

"Given that the positions of Ukrainian servicemen continue to be shelled, there cannot yet be any talk of pulling back weapons," spokesman Vladislav Seleznyov said in a televised announcement, according to Reuters.