Donald Trump has labeled President Joe Biden a "fool".

In a campaign-style video message released on the 20th anniversary of the 9/11 terror attacks, Trump accused Biden "and his inept administration" of surrendering "in defeat" by withdrawing troops from Afghanistan after two decades of war.

As the nation mourns the death of nearly 3,000 people on the 20th anniversary of the attacks, Trump released a message of his own on Saturday, September 11.

"The leader of our country was made to look like a fool and that can never be allowed to happen," the former president said, per Daily Mail.

Watch President Joe Biden's address to the nation:

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"It was caused by bad planning, incredible weakness, and leaders who truly didn’t understand what was happening."

The former president called 11 September a "very sad day" and thanked first responders, before adding: "It's also a sad time for the way our war on those who did such great harm to our country ended."

"The loss of 13 great warriors and the many more who were wounded should never have happened," Trump said of the deaths of American service members in an attack at the Kabul airport claimed by ISIS-k.

The former president, who will not attend any of the official 9/11 memorial ceremonies, said the US "will struggle to recover from the embarrassment this incompetence has caused."

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"We will live on, but sadly, our country will be wounded for a long period of time, we will struggle to recover from the embarrassment this incompetence has caused," he went on. "Do not fear, however, America will be made great again."

Per Daily Mail, the video was sent by Trump's Save America PAC in an email titled "NEW: 20th Anniversary of September 11th Address from President Donald J. Trump."

Its release comes after Trump said he will visit Ground Zero Saturday to mark the 20th anniversary - but only after Biden leaves and before he heads to host a boxing match in Florida.

He is the only surviving US president not expected to attend one of the official ceremonies.

It comes as Trump confessed that he'd like to beat up Biden.

Watch Trump make the revelation below:

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During a promotional event for a boxing match between two other fighters of advancing years - Evander Holyfield, 58, and Vitor Belfort, 44 - Trump, 75, didn't hold back admitting who he’d like to face in the ring.

"Well if I had to pick somebody in the world, not only a professional boxer because I’ll take a pass on the professional boxers - that can be a very dangerous subject," Trump told the audience via phone, per CNN.

"I think probably my easiest fight would be Joe Biden because I think he'd go down very, very quickly."

The former president added that he thought "Biden would go down in the first few seconds."

Watch President Joe Biden's address to the nation:

Watch Trump make the revelation below:

Featured image credit: Marjorie Kamys Cotera/Bob Daemmrich Photography / Alamy

Donald Trump slams Joe Biden as a ‘fool’ over Afghanistan in 9/11 video message