The White House says President Barack Obama will address the nation Wednesday evening on his plans for withdrawing U.S. troops from Afghanistan.

Spokesman Jay Carney says the president will lay out how he will implement the strategy he outlined in December 2009 on drawing down American troops.

U.S. Defense Secretary Robert Gates said Tuesday the president has to take into account sustainability at home, both in Congress and among the American public, as well as conditions on the ground in Afghanistan.

Gates acknowledged concerns in the United States about Afghanistan, saying the American people are “tired of a decade of war.” He noted there are “a lot of reservations” in Congress about the war and the level of U.S. commitment.

Defense officials have been quoted saying the withdrawal to be announced Wednesday will likely total 10,000 by the end of this year — a 5,000 initial withdrawal followed by another 5,000 by year's end. The United States currently has about 100,000 troops in Afghanistan.

A senior administration official said Mr. Obama will outline both the plan to start bringing troops home beginning in July, and future withdrawals aimed at giving Afghans control of their own security by 2014.

There is growing U.S. public dissatisfaction with the Afghan war, caused by concern about the number of casualties and the effect of the cost of the war on the economy.

Gates spoke Tuesday at the State Department, before heading to the White House with Secretary of State Hillary Clinton for consultations with the president about Afghanistan.

Mr. Obama announced the July start for the withdrawal in December 2009, when he presented his overall strategy for Afghanistan.