The United States has said it is increasing its humanitarian aid to South Sudan to $411m, funneling it through UN agencies and non-governmental organisations (NGOs).

The State Department said Washington was adding an extra $83m in aid to address the needs of South Sudanese affected by an armed conflict that has been raging since December 15.

"With this new funding, the United States humanitarian assistance is nearly $411m for fiscal years 2013 and 2014 to aid victims of the conflict in South Sudan, including internally displaced persons and refugees in South Sudan, as well as those South Sudanese who have fled to neighboring countries," the State Department said.

The aid will be channeled through UN agencies like the World Food Programme, UNICEF and the High Commission on Refugees as well as NGOs, the AFP news agency reported.

About 250,000 people have fled to neighbouring countries including Uganda, Ethiopia, Kenya and Sudan, and more than 700,000 have been displaced internally by the fighting, according to US and UN estimates.

The warring parties resumed a second round of talks on Tuesday in the Ethiopian capital Addis Ababa, where both sides have been urged to revive a moribund cease-fire signed on January 23.

Strategic interests

Fighting initially broke out within the South Sudanese army between soldiers loyal to President Salva Kiir and those loyal to former vice president Riek Machar.

It then spread, leaving several thousand dead and nearly a million South Sudanese homeless.

The fighting has been accompanied by ethnic massacres, with the political rivalries between Kiir and Machar intensified by antagonism between the Dinka and Nuer people, and the legacy of a long civil war against Sudan which ended with South Sudan's independence in July 2011.

The US, the country that has worked hardest to bring about South Sudan's creation, has stepped up pressure on the warring factions to avoid breaking up the young country.

Washington's involvement in South Sudan dates back to its support for the separatist South Sudanese forces of John Garang, who died in 2005.

Analysts say the US has both humanitarian and strategic interests in the country.

Source: Agencies