US President Trump says the US forces he is withdrawing from Afghanistan may be needed against China and Russia.
He wants to bring the American military home this year because otherwise they will be exhausted.
The United States may need them to fight China and Russia, Trump said, according to a White House reporter for the Bloomberg news agency.
Trump had previously announced on Twitter that he would prefer to have the remaining US troops in Afghanistan home for Christmas.
He has repeatedly pledged to end US involvement in the long-running conflicts in Afghanistan and the Middle East.