United States President Barack Obama. File picture: Kevin Lamarque

Washington -

President Barack Obama cleared the way on Thursday for US sanctions against anyone on either side of South Sudan's civil war who targets UN peacekeepers, threatens peace moves or abuses human rights.

The president issued an executive order allowing the use of property and asset seizures and immigration and visa bans against government or rebel officials who are judged at a later date to have transgressed.

The move comes several weeks after the United States and the European Union warned of sanctions if President Salva Kiir and rebel leader Riek Machar did not make progress in peace talks and adhere to a ceasefire deal.

White House spokesman Jay Carney said in a statement that fighting between the two sides threatened to tear their young nation apart.

“The United States will not stand by as those entrusted with South Sudan's future put their own interests above those of their people,” Carney said.

The Executive Order threatens sanctions against those who compromise peace, or who risk the security or stability of South Sudan or who obstruct the peace process, target UN peacekeepers or who are guilty of human rights abuses.

“Both the government of South Sudan and Riek Machar's rebels must immediately engage in and follow through on the inclusive peace process led by the Intergovernmental Authority on Development and resolve this conflict,” Carney said.

“They must end military actions and hold accountable those responsible for violence against civilians.

“The people of South Sudan are calling for peace. There is no room for excuses or delay.”

Peace talks mediated by the East African IGAD-bloc between the government and rebels have made little progress.

South Sudan's government has been at war with rebel groups since December 15, when a clash between troops loyal to Kiir and those loyal to sacked vice-president Machar snowballed into full-scale fighting.

Despite the brutal suffering the war has caused - displacing nearly one million people - both sides have refused to lay down their arms, violating a ceasefire deal signed in January.

Obama administration diplomacy played a high profile role in the peace push that led to the partitioning of the two Sudans into two independent nations in 2011.

In the latest outburst of violence in South Sudan, thousands of people have been killed and more than 900 000 have been forced to flee their homes. - Sapa-AFP