By Arshad Mohammed and Warren Strobel
WASHINGTON (Reuters) - Jeffrey Feltman, the top U.S. diplomat for the Middle East, is expected to leave the Obama administration to take a senior post at the United Nations, sources familiar with the matter said on Monday.
Feltman, who is assistant secretary of state for Near Eastern affairs, is expected to replace Lynn Pascoe, another career U.S. diplomat, as U.N. under-secretary-general for political affairs, a key post at the world body.
In that position, Feltman would help to formulate U.N. policy in negotiations on the Middle East peace process and other conflicts and to oversee U.N. mediation efforts.
It was not clear when Feltman might step down but one source said it could be as early as next week.
Spokesmen for the U.S. State Department and the United Nations declined comment on the matter.
Feltman has extensive experience in the Middle East, having served as U.S. ambassador to Lebanon, as head of the Coalition Provisional Authority's office in the Irbil province of Iraq and as a senior official at the U.S. consulate general in Jerusalem.
Earlier in his career, the diplomat - who speaks French, Arabic and Hungarian - worked at the U.S. embassies in Israel, Tunisia, Hungary and Haiti.
As assistant secretary of state for Near Eastern affairs, a position he assumed on an acting basis in December 2008, Feltman has covered one of the most strategically important areas of the world during a particularly volatile period.
His tenure included the "Arab Spring" of uprisings that brought down authoritarian rulers in Tunisia, Egypt and Libya as well as the conflict in Syria, where President Bashar al-Assad has sought to crush rebels trying to topple him.
Despite having made Israeli-Palestinian peace a priority, U.S. President Barack Obama has little to show for his efforts more than three years into his term. Direct responsibility for that issue, however, rested first with former special envoy George Mitchell and his successor, David Hale.
It is unclear who may replace Feltman. Secretary of State Hillary Clinton, who has made clear she plans to step down at the end of Obama's current term after four years in the job, could make an interim appointment and allow her successor to pick a permanent replacement.
(Additional reporting by Louis Charbonneau; Editing by Vicki Allen and Eric Beech)