MOSCOW -- Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry discussed the situation in Syria's northern city of Aleppo over phone on Monday evening, said the Russian Ministry of Foreign Affairs.

Lavrov said the illegal armed insurgents occupying the eastern part of Aleppo attacked civilians who tried to escape from the embattled city.

"It was their response to the humanitarian pause introduced by the Syrian authorities," the ministry noted.

Lavrov once again urged the United States to fulfill its commitment to separate the Washington-backed "moderate" opposition forces from terrorist groups.

The two diplomats agreed that both sides should keep looking for ways to stabilize the situation in Aleppo.

They also discussed other international issues, including the situation in Iraq and bilateral relations.