US Secretary of State Antony Blinken said on Saturday he had consulted with the foreign ministers of Saudi Arabia and United Arab Emirates on clashes in Sudan.
They agreed it was essential for the involved parties to immediately end hostilities without any preconditions, Blinken said in a statement.
Fighting in Sudan raged for a second day on Sunday after battles between rival generals in control since their 2021 coup killed at least 56 civilians and wounded hundreds more people, sparking international alarm.
Deafening explosions and intense gunfire shook buildings in the capital Khartoum's northern and southern suburbs as tanks rumbled on the streets and fighter jets roared overhead, witnesses said.
Violence erupted early Saturday morning after weeks of deepening tensions between army chief Abdel Fattah al-Burhan and his deputy, Mohamed Hamdan Daglo, commander of the heavily-armed paramilitary Rapid Support Forces (RSF), with each accusing the other of starting the fight.