Transcript for Trump stands by claims that FBI spied on his campaign

unsupported claims that an intelligence informant was spying on his campaign. The president on Twitter calling for action now. George Stephanopoulos is standing by with analysis. We start with David Wright at the white house. David, good morning to you. Reporter: Good morning, Dan and Diane. It's still not clear whether the reports of an FBI mole inside the trump campaign is a tempest in a teapot, or, as the president himself has suggested, something potentially bigger than watergate. The story is gaining steam, in part, with the president's help. He tweeted if the FBI or doj was infiltrating a campaign for the benefit of another campaign, that is a really big deal. Adding that only the release or review of documents held by the justice department will set the record straight. Trump's own FBI director has balked at sharing sensitive documents with the house intelligence committee, citing national security. The day that we can't protect human sources is the day the American people start becoming less safe. Reporter: Revealing a source's identity, he warned, could put American lives at risk. That hasn't stopped news organizations from speculating. According to reports, a confidential informant did meet with several key trump advisers after the FBI received evidence of suspicious contact with the Russians. Trump's lawyer used the issue to hammer the Mueller probe. I thing we're going to have to look into whether we can challenge the legitimacy of the entire investigation. Maybe a special prosecutor or special counsel should never have been appointed. A day later hrks E admitted, the president doesn't know for sure if there was a spy on the campaign. People have told us off the record, you don't know if they're right or not. Reporter: All of this would have been long before Robert Mueller took over the Russia investigation. The president and his allies are fanning this controversy even as there are new developments in the Mueller investigation. Today, "The new es" reports of another possible trump tower meeting. This one between don Jr. -- he reportedly met with an Israeli social media specialist and a representative of two wealthy Arab princes offering to mount a campaign in support of Donald Trump's candidacy. A social media campaign. This is potentially significant because if it checks out, it would mean not just Russian meddling we're talking about here, but other countries trying to meddle, as well. Dan and Diane in? So much to talk about, David, thank you. As promised, let's bring in chief anchor George Stephanopoulos. Good morning. Good morning. The story about the FBI quote unquote informant. What is your take? The word you used is important. Informant, not mole inside the campaign. The reporting is there was an informant for the FBI who had conversations with members of the trump campaign. George papadopoulos. Carter page. Not someone inside the campaign. Not someone embedded in the campaign. But a long-time source for the FBI who has worked on several other investigations, had these conversations with the members of the trump campaign. From what's been reported, seems like the conversation were relatively unexceptionable. Hard to know what came of them. But from what's been reported so far, it seems like he was pumping Carter page and George papadopoulos for information and may not have gotten that much. The way the trump team is playing it, does it strike you as good strategy in terms of sowing doubt on whether the whole investigation has a rotten root? It's not for me to judge. It's clear the strategy of president trump and the legal team is to raise questions about Robert Mueller. Is to sow doubt about Robert Mueller. This feeds into that. Trying to establish what is and is not true. What's been reported. There was an informant for the FBI. Not a mole embedded in the campaign. David referred to "The new York Times" report of Donald Trump Jr. Meeting with other foreigners. Offering to help the trump campaign. How significant is that? It depends on what happened in that meeting. You talk to Donald Trump jr.'s attorney who is quoted in the piece as well who says that he had this meeting. Nothing cam of it. The emissaries, some of them say that nothing came of it. The Israeli social media expert said he did not do work for the trump campaign. "The New York Times" also reports a $2 million payment was made from the emissary for the gulf nations to the Israeli social media company after the campaign. I think one of the big questions that Robert Mueller is going to have to determine is, what was that $2 million payment for? Was it for help to the trump campaign? That is the big question. A big question this morning among many. I want to remind everyone, George has a big show. He'll go one on one with lieutenant governor of Texas for the latest details on the deadly shooting in Santa fe. He'll speak with parents who lost children in parkland and Newtown shootings for their response to the latest school tragedy and what comes next. That's on "This week" right here on ABC.

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