U.S. envoy urges deal between Sudan's former foes

JUBA, Sudan (Reuters) - The U.S. envoy to Sudan said he would push the country's former civil war foes to clear two stumbling blocks in their faltering peace deal as he visited the state's oil-producing south on Wednesday.

North and south Sudan fought a two-decade civil war that ended in a 2005 deal, but relations have remained tense and the accord is facing key tests -- national elections in 2010 and a referendum on southern independence in 2011

Envoy Scott Gration said north and south Sudanese leaders needed to resolve wrangling over a census, a building block to elections, and preparations for the referendum.

Gration said he would meet northern and southern leaders in south Sudan's capital Juba in the latest in a series of three- way conferences to try and resolve their differences.

"We will concentrate on finding a path forward on the two remaining unresolved sticking points for full ... implementation (of the 2005 deal)," said Gration in an emailed statement.

"These are fundamental issues that must be resolved soon."

The envoy's open engagement with Khartoum has drawn criticism from human rights campaigners, who accuse Sudan of committing genocide during the conflict in its Darfur region.

A coalition of rights groups published an open letter to U.S. President Barack Obama on Wednesday, saying Gration's Sudan meetings amounted to a renegotiation of key parts of the 2005 Comprehensive Peace Agreement that would undermine the accord.

They urged Gration to take a tougher line with north Sudan's dominant National Congress Party (NCP), accusing it of using the process to postpone decisions and of encouraging tribal violence in the south.

"Left unchecked, the NCP's behavior will trigger a war in the south and make it all the more difficult to resolve the still-simmering crisis in Darfur," said the letter, signed by members of the U.S.-based Sudan Now advocacy umbrella group.

The south's dominant Sudan People's Liberation Movement (SPLM) has accused the NCP of manipulating the figures of the 2008 census and says it will reject any attempt to use the findings to demarcate constituencies.

Both sides are also discussing the terms of a long-delayed referendum bill. Insiders say one of the sticking points is what proportion of the southern electorate would have to vote for secession for it to be granted.

Most southerners, who have bitter memories of the civil war, are thought to favor independence. Many northern officials are nervous about the prospect of losing the south, which produces most of Sudan's oil wealth.

Any return to civil war would have a devastating impact on Sudan, its oil operations and the surrounding region.

A surge in tribal fighting in the underdeveloped south has raised fresh fears for its stability, and the prospects of holding fair elections across its vast territory.

Gration got a taste of the insecurity in the south, as southern soldiers shut down large parts Juba on Wednesday to carry out a door-to-door search for illegal guns. His planned press conference at a Juba conference center had to be postponed as staff and journalists got caught up in the curfew.

Two million people died and 4 million fled between 1983 and 2005 as Sudan's Muslim north and mainly Christian south battled over differences in ideology, ethnicity and religion.

The war is separate from Sudan's Darfur conflict which flared in 2003, when mostly non-Arab rebels took up arms accusing Khartoum of neglecting the remote western region.

(Editing by Andrew Heavens)