German Foreign Minister Frank-Walter Steinmeier appealed to deliver food and water to residents in the Aleppo city via UN-controlled corridors.
"The point is to prevent an even worse catastrophe for the civilian population. Therefore we urgently need UN-controlled humanitarian access to Aleppo to supply people with water and food," Steinmeier said.
He noted that it is necessary to force the warring parties to make a humanitarian pause in fighting to allow safe access to the city, which has been devastated by five years of war.
Last week Moscow and Damascus had launched a joint large-scale humanitarian relief operation in Aleppo, establishing three corridors for civilians and one for militants wishing to lay down arms.