Sudan's paramilitary Rapid Support Forces (RSF) leader General Mohamed Hamdan Dagalo, known as Hemedti, has spoken with U.S. Secretary of State Antony Blinken on the phone and "discussed pressing issues", Hemedti said on Tuesday.
"We will have another call to continuing dialogue and working hand-in-hand to forge a brighter future for our nations," Hemedti said in a post on Twitter.
He said during the ''vital conversation,'' he reaffirmed his group's ''unwavering commitment to safeguarding innocent civilians in our areas of control.''
Hemedti's whereabouts have not been disclosed since Saturday when fighting erupted between the RSF and Sudan's army.
Blinken also spoke to army chief General Abdel Fattah al-Burhan, according to the State Department.
Blinken urged both leaders to agree to a ceasefire and said both had a responsibility to "ensure the safety and wellbeing of civilians, diplomatic personnel, and humanitarian workers", the State Department said.
Mr Blinken has also tweeted saying during his separate discussions with both Dagalo and al Burhan he ''underscored the urgent need for a ceasefire.''
Sudan's battling factions both claimed to have made gains on Monday as violence cut power and water in the capital, and the U.N. envoy to Sudan said the two sides showed no signs of being willing to negotiate.
Fighting between the army and the paramilitary Rapid Support Forces (RSF) has killed at least 185 people and injured more than 1,800, said U.N. envoy Volker Perthes amid airstrikes and fighting in Khartoum and strife across Sudan. Their power struggle has derailed a shift to civilian rule and raised fears of a wider conflict.
Smoke hung over the capital, and residents reported a clamour of airstrikes, artillery fire and shooting that shut hospitals in a city unused to violence.
"The two sides who are fighting are not giving the impression that they want mediation for a peace between them right awa y," Perthes told reporters by videolink from Khartoum.
The fighting in Khartoum and its adjoining sister cities of Omdurman and Bahri since Saturday is the worst in decades and risks tearing Sudan between two military factions that had shared power during a rocky political transition.
Army chief Burhan heads a ruling council installed after a 2021 coup and the 2019 ousting of veteran leader Omar Bashir following mass protests. RSF leader Hemedti is al Burhan's deputy.
Egypt and the United Arab Emirates were also working on a ceasefire proposal for Sudan, two Egyptian security sources said.
In a speech broadcast by Egyptian state television late on Monday, Egyptian President Abdel Fattah al-Sisi said he was in regular contact with the army and RSF to "encourage them to accept a cease fire and spare the blood of the Sudanese people".
Under an internationally backed transition plan, the RSF was shortly due to merge with the army. Burhan on Monday branded the RSF a rebel group and ordered it disbanded.
Hemedti accused the army chief of being a radical ''who is bombing civilians from the air".
In comments to Sky News, Burhan said he was secure in a presidential guesthouse within the defence ministry compound. The army later said the scope of security operations was widening, which would cause restrictions on citizens' movements.
The European Union said its envoy to Sudan was assaulted in his residence on Monday but gave no details. The White House said there were no plans for a U.S. government evacuation.
