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President Obama will announce on Friday that Gen. James Jones, the national security adviser, is resigning and will be replaced by his deputy, Thomas E. Donilon, senior administration officials said.

General Jones’s departure had been long rumored, and he had previously indicated to his staff that he intended to leave by the end of the year. But the schedule was accelerated, and in recent weeks White House staff members had been increasingly critical of General Jones for statements that he apparently made to Bob Woodward, the author of “Obama’s Wars,” an account of the internal decision making on policy on Afghanistan and Pakistan.

Mr. Donilon began as a young political operative for President Jimmy Carter and later was chief of staff for Secretary of State Warren Christopher in the Clinton administration. He has long operated in the area between politics and national security. He coached Mr. Obama on foreign policy for his debates in the 2008 presidential campaign.

As deputy national security adviser, Mr. Donilon has urged what he calls a “rebalancing” of American foreign policy to rapidly disengage American forces in Iraq and to focus more on China, Iran and other emerging challenges. In the Afghanistan-Pakistan review, he argued that the United States could not engage in what he termed “endless war,” and has strongly defended Mr. Obama’s decision to withdraw American troops from Afghanistan next summer.