"Everything has been agreed with Ukraine and the International Committee of the Red Cross," he said at a news conference in Berlin.
Read MoreUkraine claims breakthrough in rebel stronghold
Russia and Ukraine have been at loggerheads over a convoy of 280 Russian trucks carrying water, food and medicine.
It has been parked for days in Russia near the border amid objections from Kiev, which believes the convoy could be a Trojan Horse for Russia to get weapons to the rebels - a notion that Moscow has dismissed as absurd.
Lavrov described the situation in east Ukraine as a "humanitarian catastrophe" and said a cease-fire was needed as civilians had been under bombardment from the Ukrainian advance.
Read MoreUkraine captures rebel building, jet shot down
"We are not able to report on positive results on reaching a cease-fire and on (a start to) the political process (to resolve the conflict)," he told journalists.
The four-month-old conflict in Ukraine's Russian-speaking east has reached a critical phase, with Kiev and Western governments watching nervously to see if Russia will use troops massed along its border to intervene in support of the increasingly besieged pro-Russian rebels.
Russian has repeatedly said it has no plans to invade and Lavrov again denied Moscow is helping the rebels. He defended the military buildup on Russia's border, saying: "We must be alert ... when several kilometers from our border a real war is underway."