Transcript for Donald Trump Jr. acknowledges that he met with Russian lawyer during campaign

Good evening, and it's great to have you with us here on a Monday night. We begin tonight with Donald Trump Jr. Acknowledging he did meet with the Russian who he thought had damaging information on Hillary Clinton. Campaigns often seek out opposites in research on their opponents, but did Donald Trump's son think he was about to get help from a Russian lawyer with ties to the Kremlin in going after Hillary Clinton? Tonight, who else was in that room and when did his father know about it? ABC's chief white house correspondent, Jonathan Karl, leading us off. Reporter: Today, Donald Trump Jr. Sarcastically dismissed concerns about his meeting last year with a Russian lawyer tied to the Kremlin, tweeting -- "Obviously I'm the first person on a campaign to ever take a meeting to hear info about an opponent. Went nowhere, but had to listen." While it is commonplace for a campaign official to meet with somebody#offering negative information about an opponent, it's highly unusual for that meeting to be with somebody lobbying on behalf of Russian interest. The meeting, which took place in trump tower last June, was attended by the very top people in the campaign. Not just don Jr., but also campaign chairman Paul manafort and trump's son-in-law, Jared Kushner. In the past, don Jr. Has denied having any contact with the Russians about the campaign. It's wow a question, you know, reads and smells like a witch hunt. Reporter: But Saturday, he acknowledged the meeting with the Russian lawyer saying, we M primarily discussed a program about the adoption of Russian children. That was a line echoed by chief of staff, reince Priebus. It seems to be on the end of the trump individuals. Reporter: But just hours later, don jr.'s story changed. He said the meeting was set up by a contact with the miss universe pageant in Moscow, by an individual who I was told might have information helpful to the campaign. He added, it quickly became clear she had no meaningful information. The president has repeatedly denied any contact between his campaign and the Russians. After his first press conference as president-elect as trump mov moved through the crowd, ABC's Cecilia Vega asked him point-blank. Did you or your campaign have any contact with Russia leading or up to the program? Reporter: No, trump said. None at all. Today white house secretary Sara Huckabee Sanders said the president learned about don jr.'s meeting over the last couple of days. No one within the trump campaign colluded in order to influence the election. All right, so let's get to Jon Karl live at the white house tonight, and we're learning the senate intelligence committee investigating Russian meddling will start interviewing former trump campaign officials this week? Reporter: And Donald Trump Jr. Says he is more than willing to talk to the committee, tweeting today, happy to work with the committee to pass on what I know, and the top Democrat on that committee, senator mark Warner says that he absolutely wants to talk to him. Donald Trump Jr. By the way, David, has now today, we have learned, hired a lawyer to deal with all issues related to that Russia investigation. All right, Jon Karl leading us off.

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