UPDATE 1-US urges Sudan to carry out North-South peace deal

* Two sides will try to prevent conflict over Abyei ruling

* Three-way talks set for July in Khartoum, August in Juba

* U.S. official says "the stakes are enormous" (Adds quotes, details)

By Arshad Mohammed

WASHINGTON, June 23 (Reuters) - The United States urged Sudan's north and south on Tuesday not to allow disputes over oil and elections to unravel the 2005 peace deal that ended their two-decade civil war.

Disagreements over how to implement the deal could drag the African oil exporter back into conflict if not settled ahead of a ruling on a disputed oil region in July, elections in 2010 and a referendum on southern secession the following year.

"The stakes are enormous," said U.S. Deputy Secretary of State Jim Steinberg, reflecting fears among officials and analysts that the civil war, in which two million people died, could erupt again. The war was separate from the Darfur conflict which continues in western Sudan.

Steinberg spoke at a U.S.-hosted conference that gathered officials from north Sudan's dominant National Congress Party, the south's Sudan People's Liberation Movement and 20 countries to try to keep the Comprehensive Peace Agreement on track.

The agreement set an interim period, with a coalition government between the Muslim north and mostly Christian south and the sharing of oil wealth. It ends in 18 months with a referendum in the south for which analysts say the government is unprepared.