US Secretary of State Antony Blinken urged the leaders of Sudan's rivaling factions on Friday to use a three-day truce reached on the occasion of Eid Al-Fitr to immediately start negotiations on a sustainable and lasting ceasefire.

Sudan has been undergoing intense fighting between the armed forces and the rival paramilitary group Rapid Support Forces (RSF) since last week. The sides agreed to a three-day truce starting Friday in connection to the Muslim holiday marked at the end of the holy month of Ramadan.

Check out: What is Eid al-Fitr?

The talks in question, according to Blinken, should address such issues as the delivery of humanitarian assistance, protection of civilians, including the withdrawal of both forces from urban areas, and security for vital health, water, power and communications, and other infrastructure.

He also reiterated his call for an end to the fighting, despite "serious mistrust between the two forces."

The US top diplomat urged both sides to the fighting on hold to enable all civilians, including diplomatic personnel, to reach safety and allow full and unimpeded humanitarian access.

Health Minister of Sudan Haitham Mohamed Ibrahim said on Friday that about 60 people were killed and more than 200 injured during the first day of Eid Al-Fitr.

This comes after the president of the International Committee of the Red Cross (ICRC) said the organization "implores" the parties to the conflict in Sudan to grant it immediate humanitarian access as provided by the rules of international law.

"The suffering is made worse by the fact that the ICRC has been unable to get aid to the people who need it most, as the parties have not given us the necessary security guarantees," she explained.

About 1,600 civilians have been killed and injured since the outbreak of clashes last Saturday, and the Sudanese Ministry of Health said a third of Khartoum hospitals are out of service.

The Sudanese Armed Forces spokesperson Brigadier General Nabil Abdallah said the military has started "gradually cleaning out the hotspots of the Rapid Support Forces in the vicinity of the capital, Khartoum."

UN Secretary-General Antonio Guterres urged the sides to commit to a ceasefire, expressing his disappointment that the UN-brokered ceasefire aimed at providing safe humanitarian corridors was only "partially" honored on Sunday.

The US joined the UN calling for an immediate ceasefire without preconditions between the two armed groups, White House National Security Council spokesperson John Kirby stated on Monday.

Sudan's paramilitary Rapid Support Forces (RSF) agreed to a 72-hour ceasefire on humanitarian grounds starting at 6:00 am local time (4:00 GMT) on Friday.

On Thursday, Blinken spoke with Sudan Army chief Abdel Fattah Al-Burhan and Mohammed Hamdan Dagalo (Hemedti), the commander of the RSF, and urged the parties to the conflict in Sudan to uphold a nationwide ceasefire until the end of the Islamic Eid Al-Fitr holiday on April 23. 

As quoted by Reuters, the RSF said that "the truce coincides with the blessed Eid Al-Fitr ... to open humanitarian corridors to evacuate citizens and give them the opportunity to greet their families."