A senior US lawmaker urged the immediate deployment of peacekeepers to Sudan's war-torn border region of Southern Kordofan, warning of a risk of "genocide" by government forces.

South Sudan last month broke away from Sudan to become the world's newest independent nation but violence has persisted in Southern Kordofan, an oil-producing region that remains under Khartoum's rule.

Representative Chris Smith, who heads the House Foreign Affairs subcommittee on Africa, on Friday said there were credible signs of systematic attacks by Sudan's Arab and Muslim forces against the largely Christian Nubian people.

"There has been far too little interest shown and there are no UN peacekeepers to help provide at least some semblance of protection. So the people are just being mowed down," Smith said in an interview on C-SPAN's "Newsmakers" program to air on Sunday.

"We have another potential genocide -- certainly mass killing -- because of who they are, their ethnicity and their faith," Smith said.

Smith urged the deployment of peacekeepers, citing the example of another disputed Sudanese region, Abyei, where the United Nations authorized a 4,200-troop Ethiopian force ahead of the independence of South Sudan.

"A deployment immediately could be very effective in mitigating the loss of life," Smith said.

Smith on Thursday convened an emergency congressional hearing where Andudu Adam Elnail, the Anglican bishop from Southern Kordofan's capital Kadugli, charged that Sudanese troops were deliberately targeting civilians.

Elnail said forces were going door-to-door to kill perceived rebel supporters. The bishop asked for the assistance of US satellites to identify alleged mass graves.

Smith said that a bombing campaign has also prevented people from tending to crops, meaning that tens of thousands of people risked hunger.

South Sudan's independence was part of a 2005 peace deal halting a two-decade war that killed two million people. The United States has moved to take Sudan off a blacklist of state sponsors of terrorism as a reward for its cooperation, including its prompt recognition of the South's independence.

Khartoum has sought better relations with the United States, including a lifting of sanctions, but has insisted that Southern Kordofan is a domestic issue after the implementation of the peace deal.

"A conversation must be had with Khartoum about lifting sanctions, but in the context of ending South Kordofan attacks and all the other human rights abuses that are being committed," Smith said.

A separate conflict erupted in 2003 in Darfur pitting ethnic rebels against the Arab state. The International Criminal Court has issued an unprecedented arrest warrant for Sudan's President Omar al-Bashir over charges including genocide in Darfur.