Oklahoma Republican Sen. James Lankford says text messages critical of President Trump sent by senior FBI officials who worked on Special Counsel Robert Mueller's team won't "taint" the overall probe into Russian interference in the election.

"I don't think it taints the entire process. But it certainly taints that season of it. And it's something you should look at with any political investigation that he was on at the time. Again, we want our F.B.I. agents to be neutral and to be non-political," said Lankford on CBS News' "Face the Nation" on Sunday.

FBI agent Peter Strzok sent the messages to his colleague Lisa Page, a senior FBI lawyer who also worked on the Mueller team. Some of the 375 messages exchanged included disparaging comments about then-candidate Trump, including messages calling Mr. Trump an "idiot."

Strzok was removed from the Mueller investigation in August over the messages.

Strzok had also worked on the FBI investigation into former presidential candidate Hillary Clinton's use of a private email server while at the State Department. Lankford, who serves on the Senate Intelligence Committee, said Strzok had a "strong bias" against Mr. Trump, and his work on the Mueller probe should be examined.

"It's very serious to be able to have someone inside. What they've got to determine is: Was he directing the investigation one way or the other while he was on the investigation? Is that something they can go back, and repair, and look, and see if there's any kind of bias that's in it?" questioned Lankford.

The Senate Intelligence Committee is conducting its own probe into Russian interference in the 2016 election. Lankford said he has "no doubt" that the Russians will continue to interfere in U.S. politics.

"There's no doubt the Russians not only engaged in our past election but they're still trying to find ways to be able to do that. We've noted several ways publicly in the last couple of months that they're still engaging in social media, trying to stir up the United States controversies," said Lankford. He said Russian efforts are aimed at "adding fuel to the flame" when it comes to divisive issues.

.@SenatorLankford says “no doubt” Russians did and are still trying to interfere with integrity of US election process. pic.twitter.com/2UPEzQ8szK — Face The Nation (@FaceTheNation) December 17, 2017

"I compare it to if you've got two kids in a playground that are in a fight, there's always somebody on the edge of the playground screaming, 'Fight, fight, fight,' trying to bring a bigger crowd to it," he said.

Lankford said he and a bipartisan group of lawmakers are working to finalize a bill that would strengthen election security in response to Russian efforts to interfere in 2016 races.

"The F.B.I. was much too slow and Homeland Security were much too slow in notifying our states the last time that the Russians were trying to probe election systems. We've got to be able to do that faster. We've got to help states have a good, reliable, auditable election system that they can actually do themselves and that the federal government and that all entities from those states can trust those election results," suggested Lankford.

Meanwhile, the Oklahoma Republican said he's confident the GOP-crafted tax bill will spur economic growth.

"The target of any time you do tax reform is to try to reduce taxes on individuals and on businesses so they have more money to spend. They can spend that money, that encourages the economy to grow. We know it will grow. Now the guess is how much," said Lankford.

"We've got to get the economy growing again. We're not growing again. We never do get on top of the debt and deficit without that," he added.

Lankford also responded to criticism from Democrats on Capitol Hill that the tax bill had been rushed through, saying the process has been "12 months in the making."

"The House released out their proposal on tax reform in January of this year, the White House early in the summer. This has not been a rushed process," Lankford said. "This has literally been 12 months in the making, and multiple hearings over the past year, and then leading back to earlier work even that was done several Congresses ago."

He added, "So I know that the theme of this has been, 'It's been rushed.' I think it's because a lot of people haven't started paying attention till the very end. But the process has been long and methodical."