Transcript for Former CIA Director John Brennan testifies on Russia investigation

On 4 August of last year I spoke to Alexander port copped the head of Russia's federal security bureau the FSB. I next raised the published media reports of Russian attempts to interfere in a upcoming presidential election. I told to support a cough that if Russia had such campaign underway there would be certain to backfire. Finally I warned missed abort a cough that if Russia pursued this course it would destroy any near term prospect for improvement in relations between Washington and Moscow. And would undermine constructive engagement even on matters of mutual interest. When I repeated my warning he again denied the charge but said that he would inform prison prudent of my comments. I believe I was the first US official to brace the Russians. On this matter. Having been involved in many counterintelligence. Cases in the past I know what the Russians try to do they try to suborn individuals. And they try to get individuals including US persons to act on their behalf either wittingly or unwittingly. And I was. Worried by a number of the contacts at the Russians had with US persons. And so therefore by the time I left office on January 20 I had unresolved questions in my mind as to whether or not the Russians had been successful. In getting US persons. Involved in the campaign or not to work in their behalf again either in a weeding or unwitting fashion and so. Therefore I felt as though the FBI investigation. Was. Certainly well founded and needed to look into those issues.

This transcript has been automatically generated and may not be 100% accurate.