President Barack Obama will announce in his State of the Union address that 34,000 US troops will withdraw from Afghanistan within a year, two people familiar with his remarks said Tuesday.

The move marks the next phase in the administration's plans to formally withdraw most foreign combat troops by the end of 2014.

The White House has said it would be open to leaving no troops in Afghanistan, though it's likely that a small presence will remain, in keeping with the Pentagon's preferences.

The people familiar with Obama's remarks requested anonymity in order to discuss the troop drawdown ahead of the president.

Obama discussed the next phases of the drawdown with Afghan President Hamid Karzai during a day-long meeting in Washington last month, the first meeting between the two leaders since Obama's re-election. The two leaders agreed to accelerate their timetable for putting Afghan forces in the lead combat role nationwide, moving that transition up from the summer to the spring.

Obama will announce the troop drawdown and the future of the US role in Afghanistan during a joint session of Congress that is otherwise expected to be dominated by the economy and other domestic issues.

The Obama administration gave the first clear signal in early January that it might leave no troops in the country after December 2014. Administration officials have said they are considering a range of options for a residual US troop presence of as few as 3,000 and as many as 15,000.