WASHINGTON — Republican Senator Lindsey Graham on Sunday harshly condemned Saudi Crown Prince Mohammed bin Salman over his alleged role in the killing of journalist Jamal Khashoggi, calling him "unhinged" and pointedly refusing to work with the prince in the future.

"The fact that he didn’t know about it is impossible for me to believe," Graham said on Sunday's "Meet The Press." The South Carolina senator said he hasn’t been given an official briefing on the matter, but maintained that the conclusion that the crown prince had a role in Khashoggi's murder should be clear to anyone with knowledge about the country.

“If he is going to be the face of Saudi Arabia going forward, I think the kingdom will have a hard time on the world stage,” Graham added. “They are an important ally, but when it comes to the crown prince, he is irrational, he is unhinged, and I think he has done a lot of damage to the relationship between the United States and Saudi Arabia and I have no intention of working with him ever again.”

The United States announced sanctions this week against 17 Saudi Arabian officials over the killing of Khashoggi at the Saudi consulate in Istanbul, Turkey.

NBC News reported on Friday that the CIA has concluded that the crown prince himself ordered the assassination.

Graham said he doesn’t want to let the individuals who carried out the killing to become “the fall guy,” but instead, “I am going to do whatever I can to place blame where I believe it lies: I am going to put it at the feet of the crown prince who has been a destructive force in the Mideast.”

The senator noted that he previously had a lot of hope for the prince’s potential as a reformer in the region, but “that ship has sailed as far as Lindsey Graham is concerned.”

Graham's language on Saudi Arabia stands in stark contrast to President Trump, who repeatedly told "Fox News Sunday" this weekend that the crown prince has continually denied involvement in the incident.

Asked whether the prince was lying, Trump responded, “he told me that he had nothing to do with it. He told me that, I would say, maybe five times at different points.”

The president also asked, “Will anybody really know? He did have certainly people that were reasonably close to him and close to him that were probably involved.”

On Sunday, Graham was asked about the bond between the crown prince, Trump, and Jared Kushner, and he said, “I’ll leave it up to the president to find out how to handle Saudi Arabia from the executive branch side.”

"From the legislative branch side, we’re going to do as much as we can, as hard as we can, to send a signal to the world," he continued. "This is not how we expect an ally to act. What happened in Turkey violates every norm of civilized society and it will not stand. And if John McCain were alive today, he’d be the first one saying that."

Graham also maintained that the Saudi ambassador to the U.S., the crown prince’s brother, Prince Khalid Bin Salman, should not be allowed back in to the United States as ambassador.

Also on "Meet The Press," Graham publicly called on the president to move forward on the issue of criminal justice reform, asking him to “pick up the phone” and lobby Senate Majority Leader Mitch McConnell to bring their bill on the issue to the floor.

“The Republicans are the problem here, not the Democrats,” Graham said.