Us President Joe Biden visited the Volunteer Fire Department in Shanksville, Pennsylvania on Saturday, on the 20th anniversary of the September 11 attacks.

Biden told reporters in Shanksville, where one of four planes struck 20 years ago, that the US cannot invade every place where al-Qaeda is and leave its troops there.

The President honored the group of passengers on United Airlines Flight 93 who took control of the cockpit and steered the jet into an empty field, calling them true heroes.

At flight 93 memorial, Former President George W. Bush expressed concerns over the current division occurring in the country and the future of the US. He detailed that he was proud to lead a resilient and united nation in the aftermath of the attacks in 2001. 

Biden tweeted that the nation must never forget those lost in the attacks, who are estimated at 3,000 people.

Twenty years ago, nearly 3,000 lives were cut short by an unspeakable act of cowardice and hatred on 9/11. As a nation, we must never forget those we lost during one of the darkest moments in our history and the enduring pain of their families and loved ones.

— Joe Biden (@JoeBiden) September 11, 2021

On the other hand, former US President Donald Trump used the 20th anniversary of the 9/11 attacks to criticize Joe Biden in a video message on Saturday, accusing him of "incompetence" in light of the Afghanistan withdrawal.

The former one-term President attributed this to "bad planning" and "incredible weakness" because leaders "truly didn't understand what was happening." 

US Defense Secretary Lloyd Austin reaffirmed the US' capability of handling threats in Afghanistan in an interview with CNN earlier Saturday.

Biden paid visits to the September 11 monument in Manhattan, the Flight 93 memorial in Shanksville, and the Pentagon in Arlington, Virginia on Saturday, though he did not make any public statements.