Damascus (AFP) - Syria's government has "approved" a ceasefire deal brokered by its Russian ally and the United States, state news agency SANA reported on Saturday.

"The Syrian government has approved the agreement, and a cessation of hostilities will begin in Aleppo for humanitarian reasons," the agency wrote.

Citing "informed sources", it said one of the accord’s goals was "reaching the necessary political solutions for Syria".

The deal agreed by Moscow and Washington calls for a halt to fighting across the country and increased humanitarian aid for the battered city of Aleppo.

Specifically, it calls for a "demilitarised zone" around the Castello Road leading into Aleppo so that desperately needed assistance can get into the city.

If a cessation of hostilities holds for one week, the US and Russia -- which back opposing sides in the war -- could start joint operations against jihadist groups.

"The entire agreement was reached with the knowledge of the Syrian government," SANA wrote.

The opposition High Negotiations Committee on Saturday said it had yet to receive "the official text" of the agreement.

"If we receive it, the HNC will study its details and the mechanisms of its implementation," it wrote on its Arabic-language website.

Leading HNC member Bassma Kodmani told AFP that her group "cautiously welcomed" the deal but was sceptical that Damascus would comply.