President Trump says the U.S. relationship with Russia is being "greatly hampered" by the ongoing investigation into Russian interference in the 2016 election, and he called an FBI agent who was removed from the probe over his anti-Trump texts a "disgrace to our country."

"I think we're greatly hampered by this whole witch hunt that's going on in the United States. The Russian witch hunt. The rigged situation," said Mr. Trump in an interview with "CBS Evening News" anchor Jeff Glor at his golf course in Turnberry, Scotland on Saturday.

The remarks come just before his meeting on Monday with Russian President Vladimir Putin in Helsinki, Finland.

Mr. Trump has repeatedly characterized the Mueller probe as a "witch hunt." On Friday, Deputy Attorney General Rod Rosenstein unveiled an indictment naming 12 Russian intelligence officials accused of a conspiracy to break into Democratic computer systems and release stolen emails.

In the interview Saturday, Mr. Trump also criticized embattled FBI agent Peter Strzok as a "disgrace to our country" and the FBI for anti-Trump text messages he exchanged with another FBI official during and after the 2016 campaign while deeply involved in the Clinton email investigation. The president commented on Strzok's fiery testimony on Capitol Hill on Thursday, a day-long lambasting of the agent's alleged bias that Strzok denied had affected his decision making.

"I watch some of the testimony, even though I'm in Europe, of Strzok. And I thought it was a disgrace to our country. I thought it was an absolute disgrace. Where he wants to do things against me before I was even, I guess before I was even the candidate. It was a disgrace. And then he lied about it. And you know, talking about shutting it down and 'we, we.' And he says, 'Oh, I meant the American people' all of a sudden, you know. He came up with excuses," said Mr. Trump.

The president said the Russia probe could potentially impact the U.S.' relationships with other countries as well, calling into question what he characterized as the politicization of the overall investigation.

"I think it's a disgrace what's going on. And then you look how, you know, partisan it is. You look at what's going on where -- and they know, they know that there's no way he can get away from those horrible texts that he wrote. So the other side does. But it's a very partisan thing," he said.

More of Glor's interview will air Monday on "CBS This Morning," between 7 a.m. and 9 a.m., and on "CBS Evening News with Jeff Glor" Monday from 6:30 p.m. to 7 p.m.