The US has accused the Sudanese paramilitary Rapid Support Forces (RSF) of committing genocide and imposed sanctions on its leader.

US Secretary of State Antony Blinken on Tuesday said Mohamed Hamdan Dagalo, also known as Hemedti, was being punished for his role in "systematic" atrocities against the Sudanese people during the 20-month conflict.

He said the RSF and allied militias were responsible for the murder of "men and boys - even infants", as well as brutal sexual violence against women on ethnic grounds.

The militias have also targeted fleeing civilians and murdered innocent people escaping the conflict, Blinken said.

"Based on this information, I have now concluded that members of the RSF and allied militias have committed genocide in Sudan," he said.

In response, the RSF has accused the US of double standards and for failing to effectively address the ongoing crisis.

"The decision… expresses the failure of the [US President Joe] Biden administration to deal with the Sudanese crisis and the double standards it followed [with regards to the crisis]," Hemedti's adviser, El-Basha Tbaeq, said in a post on his X account.

He added that this may complicate the Sudanese crisis and hinder negotiations to address the root causes of the conflict.

The RSF has been fighting the Sudanese military since April 2023, and there has been a growing outcry about its conduct during the war.

Both sides have been accused of atrocities, with the conflict leading to one of the world's worst humanitarian crises.

In May, US special envoy for Sudan Tom Perriello said that some estimates suggested up to 150,000 people had been killed in the conflict.

Famine has been declared in several parts of the country, with 24.6 million people - about half the population - in urgent need of food aid, according to experts.

Mr Blinken said neither the RSF nor Sudan's military were fit to govern Sudan.

"Both belligerents bear responsibility for the violence and suffering in Sudan and lack the legitimacy to govern a future peaceful Sudan," he said.

The sanctions bar Hemedti and his immediate family members from visiting the US, and any personal assets there are blocked.

Seven RSF-owned companies based in the United Arab Emirates and one other individual are also being sanctioned for helping the paramilitary group procure weapons.