U.S. President Barack Obama said on Friday that the United States as a nation remains committed to peace in the Middle East.

In a statement on the resignation of his Middle East special envoy George Mitchell, Obama said: "As a nation, we remain committed to peace in the Middle East and to building on George's hard work and progress toward achieving this goal."

He spoke highly of Mitchell, saying the latter has worked as a "tireless advocate for peace" as the special envoy over the past two and a half years.

"His deep commitment to resolving conflict and advancing democracy has contributed immeasurably to the goal of two states living side by side in peace and security," the president added.

Mitchell, who brokered the historic Good Friday agreement in Northern Ireland in 1998 ending decades of bitter conflict, wrote to Obama about his intended resignation effective on May 20.

His resignation came at a time when Obama is scheduled to deliver a speech on the events in the Middle East and North Africa and U.S. policy in the region at the State Department. The president will also meet at the White House with two key regional players -- King of Jordan Abdullah II and Israeli Prime Minister Benjamin Netanyahu -- respectively on Tuesday and on Friday.

U.S. Secretary of State Hillary Clinton described Mitchell as a man who represents the best traditions of American diplomacy, pledging to "carry forward his commitment to pursue a comprehensive peace in the Middle East."

Obama accepted Clinton's recommendation by naming Mitchell's deputy David Hale to serve as the acting envoy, saying he has every confidence in Hale's ability to continue to make progress in this "important effort."

The Israelis and the Palestinians launched direct talks in early September last year under the auspices of the Obama administration. But the talks ran aground two weeks later due to Israel's intransigence on the issue of settlement building on occupied land.