"Despite their courage and great sacrifice, thousands of LGBTQI+ service members were forced out of the military because of their sexual orientation or gender identity. Some of these patriotic Americans were subject to court-martial, and have carried the burden of this great injustice for decades," Biden said in a statement.

He said that with the gesture he was "ensuring the culture of our Armed Forces reflect the values that make us an exceptional nation."

The decision specifically concerns Article 125 of the Code of Military Justice, dating from 1951 and made obsolete by Congress in 2013. It made sodomy between consenting adults a crime punishable by court-martial.

A senior US official told reporters that thousands of people could be eligible for pardons.

Along with the symbolism, anyone granted clemency will also be able to have their military documents amended -- which could in turn make them eligible for benefits they had previously been denied.

The United States barred homosexual personnel from serving in the military until 1994, when a policy known as "Don't Ask, Don't Tell" went into effect.

That policy prevented service members from being asked about their sexual orientation, but still required gay, lesbian and bisexual personnel to remain closeted to avoid being dismissed from the military until its repeal in 2011.

In September 2023, the Defense Department announced that it would conduct a review to identify veterans who received other than honorable discharges -- which can affect access to benefits as well as harm employment prospects -- as a result of their sexual orientation, so their records can be corrected if merited.