WATCH: 9/11 family member explains why they don't want Biden to attend anniversary events

Tucker Carlson interviewed Brett Eagleson one of the 9-11 family members Tuesday night on Fox News. Brett lost his father on 9-11 and like many of the family members doesn't want President Joe Biden to attend the 20th anniversary memorial events unless he declassifies American intelligence documents detailing what the government knew about the attacks before 911.

Carlson began, "It's hard to believe that as we approach the 20 year anniversary, the US government, through all these different administrations, has continued to hide intel about what it knew before 9-11. Why are they hiding this? Did you have any good theories?"

Eagleson replied, "Tucker, I don't know the answer to that, and I wish somebody would provide it to us, but the justification for our government secrecy itself is classified. So, the government has invoked what's known as the State Secrets Principle on all documents related to Saudi Arabia's involvement in 9-11 and the justification for that principle itself is classified. So it's ...painstakingly hard for us as family members to be 20 years on and still be begging our government for closure."

"We have begged everyone. We have... met with Senators from both sides of the aisle. We have begged from administration to administration and the US government abandoned Americans in Afghanistan, just like they're abandoning the 9-11 families... it's a really hard thing to come to terms with Tucker, that your government doesn't have your back."

"We've been fighting. I've been on your show a handful of times...I've been on CNN... it's just astonishing to me Tucker, why our government fails to release this information. And the message to President Biden remains, that unless you honor your campaign promise to us, don't bother coming to 9-11, because we refuse to go through another ceremony where a political leader stands up and says that how much 9-11 means to them and how much they grieve for us and how important it is. Yet behind closed doors, thwart us, thwart our efforts and thwart closure."

Tucker responded, "I just got to say, I don't believe for a second this has anything to do with Saudi Arabia. Nobody cares about Saudi Arabia. This is protecting, I think US officials, Americans, like how did they screw up? I mean, if history is any guide, the people that are protecting are usually themselves."

Carlson asked about the theory of Saudi involvement Eagleson answered, "...there's a lot of theories, right? And the biggest theory out there is embarrassment. Embarrassment by our own intelligence failures. Embarrassment because of the fact since day two, we probably knew that the Saudis were very much involved, but yet we started a war in Iraq."

Eagleson continued, "One point I just wanted to make, your former colleague, Catherine Herridge just broke this story which was lost in the whole shuffle of Afghanistan over the weekend... about a pilot... Brown was his name, who was approached by the FBI in 2012, about a document that the FBI found in a Saudi government employee's apartment. Do you know what that document was Tucker? It was a diagram of how to fly a plane into a building. How much more of a smoking gun can it get than that? But somehow this document gets lost in the news of Afghanistan and some part of our government. Like they're justified in keeping this information from me and from thousands of other family members. What reason is it that our government continues to keep this information under lock and key?"

"There is a crew, there is a group within the FBI as we speak, as I sit here today, I assure you, there is a group within the FBI that was there prior to 911. And that they use the bureaucracy to prevent this information from seeing the light of day. And we need a President that's going to stand up for once and for all and take our side."