President Barack Obama in his State of the Union address Tuesday night will announce that 34,000 U.S. troops will return from Afghanistan by this time next year, according to a senior administration official.

That will reduce troop levels in that country by half. Further reductions will occur next year.

Lawmakers and the public alike have been awaiting a decision by the administration regarding troop levels in Afghanistan, where the U.S. is set to officially end combat operations in 2014.

Ben Rhodes, deputy national security adviser, revealed last month that the White House is considering fully withdrawing troops after that date.

"That would be an option that we would consider," Rhodes responded on a conference call with reporters when asked if a full drawdown of troops after 2014 is possible. He added that the U.S. objective is not to keep troops in Afghanistan, it's making sure there is no haven for al-Qaida in Afghanistan and ensuring that the Afghan government has a sufficient security force.

But the senior administration official said the president on Tuesday will not be making further announcements about troop levels beyond the 34,000 announcement.

Afghanistan troop-level decisions and when and how to reveal them remains much debated in Washington.

In an exclusive interview with Yahoo News last week, Sen. Bob Corker of Tennessee, ranking Republican on the Senate Foreign Relations committee, advised the president to wait to decide on the pace of U.S. troop withdrawal until after Afghanistan's 2014 elections.

“The biggest factor in the success of Afghanistan likely is to be the elections, and how that’s handled, and who’s elected, and the process,” Corker said. “I don’t understand why a decision has to be made now as to the number of troops.

"We could wait and decide how many troops are going to be on the ground,” Corker continued. “But our allies are really—really worried—worried about us making a decision that really takes us to levels that allow the gains that have been put forth to dissipate.”

Corker bluntly declared in that interview that he does not trust Afghan President Hamid Karzai, and vowed to make sure the State Department carries out reforms proposed in response to the deadly terrorist attack against the U.S. compound in Benghazi, Libya, last September.

Olivier Knox contributed to this story.