Washington - President
"In the last two and a half years, George Mitchell has worked as an advisor who was tirelessly for peace as U.S. special envoy to the Middle East," Obama said.
Obama declared, in 2009 Mitchell had agreed to hold that office for two years, and in fact has served longer, although there is a deep frustration with the stagnation of the Israeli-Palestinian peace efforts.
"He has received the toughest jobs imaginable and perform many hours of grueling to advance U.S. interests and problems of peace"Obama said.
"As a nation, we remain committed to peace in the Middle East and to build based on George's hard work and progress towards the achievement of that goal."
The President said that Secretary of State has asked deputy Middle East envoy David Hale to temporarily take over the functions of Mitchell.
Mitchell's resignation was before Obama's speech is expected to explain the new strategy of its Middle East and Israeli Prime Minister 's visit to the White House.
Mitchell, 77, a former U.S. senator who has been brokering the peace agreement in Northern Ireland, is one of the first member of Obama's foreign policy team that was announced and has traveled shuttle between Washington and various Middle Eastern capital to seek new talks.