A letter from the alleged mastermind of the 9/11 attacks has been delivered to President Obama

A letter from Khalid Sheikh Mohammed, who is accused of being the mastermind behind the 9/11 attacks, to President Barack Obama has been delivered to the White House nearly three years after it was written.

Mohammed wrote a letter to the president complaining about "Muslim oppression at the hands of the West" and the US's role in Gaza in 2014, according to The Miami Herald's Carol Rosenberg, who was the first to report on its existence.

Mohammed, who is accused of mass murder, has been held in a secret prison at Guantanamo Bay, Cuba, since 2006, and his communications with the outside world have been strictly managed. Pentagon officials had declined to deliver the letter because they viewed it as "propaganda," according to CBS News.

The Army judge overseeing Mohammed's case overruled that view and ordered prosecutors on January 6 to deliver the letter to the president, Rosenberg reported on Monday. CBS reported on Tuesday that the White House received the letter but declined to discuss its contents.

The judge's ruling — still under seal on the Military Commissions website — said there was no "legal basis" for the secrecy surrounding the letter and gave prison officials 30 days to scrub it for any security concerns before releasing it to the public, The Miami Herald reported.

If that timeline holds, the letter will appear on the Military Commissions website sometime around February 5.

Mohammed is awaiting trial on charges related to his role in the Al Qaeda terror group. He is accused of planning the 9/11 attacks, which he admitted to being responsible for "from A to Z," according to a military transcript.

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