Middle East envoy resignation comes at tough time for Obama

President Obama's special envoy to the Middle East is resigning as the region dominates more of the president's time and focus.

The resignation of George Mitchell, the celebrated diplomat and Obama's special envoy for Middle East peace talks, comes as Obama is preparing to welcome key players to the White House and deliver a major address on the region.

Obama said in a statement Friday afternoon that Mitchell "told me when he took this job that he would put in a couple of years, and I’m so glad he did."

"He is — by any measure — one of the finest public servants that our nation has ever had," Obama said.

The president said Secretary of State Hillary ClintonHillary Diane Rodham ClintonMatt Gaetz ahead of Mueller hearing: 'We are going to reelect the president' What to expect when Mueller testifies: Not much McConnell challenger faces tougher path after rocky launch MORE has asked Mitchell's deputy, David Hale, to fill the role as acting envoy.

"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," Obama said.

The president was effusive in his praise for Mitchell's service.

"Over the past two and a half years, George Mitchell has worked as a tireless advocate for peace as the U.S. Special Envoy for the Middle East," Obama said. "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 White House also released the text of Mitchell's resignation letter, in which the longtime foreign relations expert said he strongly supports Obama's "vision for comprehensive peace in the Middle East."

"When I accepted your request to serve as U.S. Special Envoy for Middle East Peace my intention was to serve for two years," Mitchell wrote to the president. "More than two years having passed I hereby resign, effective May 20, 2011. I trust this will provide sufficient time for an effective transition."

Obama spokesman Jay Carney said earlier in the day that no one at the White House was under any illusion that forging a lasting peace in the Middle East would be easy.

The president is preparing to welcome Jordanian King Abdullah to the White House on Friday and Israeli Prime Minster Benjamin Netanyahu on Friday.

On Thursday, Obama will deliver a major address from the State Department on upheaval in the Middle East.

Carney said Obama would reflect on the "remarkable period" of revolution the region has experienced this year, and on U.S. policy for a region undergoing a transformative period.

Carney said the president will deliver a "fairly sweeping and comprehensive speech" from Foggy Bottom that targets a broad audience. He added that Obama will discuss the killing of bin Laden and how the violent extremism promoted by the terrorist mastermind is a tactic that is being replaced by nonviolent protests in the region.

Carney said Obama will discuss how people like bin Laden "are fast moving toward, if you will, the dustbin of history."

—An initial version of this was published at 12:15 p.m.