President Barack Obama is expected to announce on Tuesday that the United States plans to keep just under 10,000 troops in Afghanistan after this year, if the Afghan government signs a security agreement.

A senior administration official said that number would be cut by roughly half by the end of 2015.

There currently are 32,000 American forces in Afghanistan, where the United States has fought its longest war.

Both presidential candidates in Afghanistan have indicated a willingness to sign the security agreement, if elected.