Washington and Riyadh announced the latest deal, as well as brokering the previous week-long truce.

In a joint statement, they acknowledged that the ceasefire had not been fully observed, but said it had allowed the delivery of aid to two million people in Sudan.

The UN World Food Programme said the relative lull in fighting had allowed it to send supplies to residents trapped in the capital, Khartoum, for the first time since fighting erupted six weeks ago.

The Sudanese army and its rivals from the Rapid Support Forces (RSF) have accused each other of repeated violations, particularly in the Darfur region.