In the latest chapter of President Trump's outbursts against federal law enforcement entities, he eviscerated his attorney general and the FBI in an interview with the Hill.TV, claiming what has been happening at the FBI is like a "cancer" and, "I don't have an attorney general."

The president also told the Hill.TV he had not read the slew of documents related to the Russia investigation that he ordered the Justice Department and Director of National Intelligence to declassify earlier this week. But Mr. Trump said he believes the documents will show the FBI initiated the case as a political "hoax," and said he expects exposing corruption at the FBI could be the "crowning achievement" of his presidency.

Asked what he hopes the outcome will be of his longtime battle with the FBI, the president told the Hill.TV, "I hope to be able put this up as one of my crowning achievements that I was able to...expose something that is truly a cancer in our country."

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The president again cited Sessions' recusal from the ongoing Russia probe, said he is "very disappointed" with his attorney general.

It's the most recent attack the president has made since telling Fox News last month that Sessions "never took control" of the Justice Department. In response to those attacks, Sessions, in a rare move for the nation's top cop, said that he would "not be improperly influenced by political considerations." Mr. Trump meanwhile says he's saddened by Sessions' performance in light of his early support of the Trump campaign.

"I'm so sad over Jeff Sessions because he came to me. He was the first senator that endorsed me. And he wanted to be attorney general, and I didn't see it," he said.

Mr. Trump added, "And then he went through the nominating process and he did very poorly. I mean, he was mixed up and confused, and people that worked with him for, you know, a long time in the Senate were not nice to him, but he was giving very confusing answers. Answers that should have been easily answered. And that was a rough time for him."

The president, however, appeared to suggest his disdain for his attorney general goes farther than just his recusal from the Russia investigation, citing issues at the southern border. "I'm not happy at the border, I'm not happy with numerous things, not just this," he said.

The president reiterated those frustrations on the White House South Lawn on his way to North and South Carolina Wednesday, saying he's disappointed in Sessions for a number of reasons.

CBS News' Paula Reid reports that despite the president's disappointment, Sessions has done almost everything within his authority to appease the Mr. Trump's long-promised agenda for tackling immigration issues including expedite deportations, end the Obama-era Deferred Action on Childhood Arrivals (DACA) program, staff up immigration courts, limit the number of asylum seekers and block grants from sanctuary cities.

Asked if the president would move to finally fire Sessions from his post amid months of ongoing public attacks, Mr. Trump told The Hill, "We'll see what happens."

"A lot of people have asked me to do that. And I guess I study history, and I say I just want to leave things alone, but it was very unfair what he did," he said.

He added, "We'll see how it goes with Jeff. I'm very disappointed in Jeff. Very disappointed."

Mr. Trump also told the Hill.TV that he doesn't like the term "deep state" that some conservatives use to describe a perceived group within the administration that would oppose the president.

The president also seemed to suggest the wall he saw at the Flight 93 memorial last week is an inspiration as he looks to erect a border wall along the southern border.

"So, we are building the wall, I could build it — you know what I do best is build — I could build the whole thing in a year, but um, there was a picture that was sort of great," the president told the Hill.TV. "I wish I had it. I had a picture of where I was this weekend. They built this gorgeous wall where the plane went down in Pennsylvania. Shanksville. And I was there. I made the speech. And it's sort of beautiful, what they did is incredible. They have a series of walls, I'm saying, 'It's like perfect.' So, so we are pushing very hard."

CBS News' Kathryn Watson contributed to this report.