"No. It was just a nothing. There was nothing to tell," Donald Trump Jr told the Fox network's "Hannity" show.
Hours earlier, he released a series of emails detailing an agreement to meet the Russian intermediary, who had promised to dish dirt on Clinton from Moscow. "It was literally just a wasted 20 minutes, which was a shame," he added.
The emails revealed Donald Trump Jr was told by an interlocutor that he could get "very high level and sensitive information" that was "part of Russia and its government's support for Mr. Trump."
The 39-year-old Donald Jr -- who now runs the family real estate business in his father's stead -- responded "if it's what you say I love it" and set up a meeting with the source, according to the emails.
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The email chain, released in its entirety by Donald Jr on his Twitter account, added fuel to the political firestorm swirling over allegations that Trump's campaign team colluded with Moscow to influence the 2016 election.
US intelligence agencies have concluded that Russian President Vladimir Putin approved a mass effort to tilt the election in Trump's favor, including hacking and leaking embarrassing emails from Democrats.
The email disclosure now thrusts the president's son at the center of multiple US investigations by Congress and by the FBI as to whether Trump's team was in the know.
Info to 'incriminate Hillary'
Donald Jr had initially dismissed the meeting he arranged with the Russian lawyer, Natalia Veselnitskaya, as having to do with adoptions, but then offered shifting explanations as more details emerged.
In the emails released Tuesday, Rob Goldstone -- a publicist close to the Trumps -- tells Donald Jr that he has learned of a Russian offer of compromising material on Clinton from a pop singer he represented, Emin Agalarov.
"The Crown Prosecutor of Russia met with his father Aras this morning and in their meeting offered to provide the Trump campaign with some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father," Goldstone wrote in a June 3, 2016 email.
"This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr. Trump - helped along by Aras and Emin," he added.
Donald Jr responded less than 20 minutes later, according to the chain of emails entitled "Russia - Clinton - private and confidential."
"Thanks Rob I appreciate that. I am on the road at the moment but perhaps I just speak to Emin first. Seems we have some time and if it's what you say I love it especially later in the summer."
The email exchange took place as Clinton had all but secured the Democratic nomination and Trump was casting one eye toward the general election campaign that would begin that summer.
In an interview with NBC News, Veselnitskaya said: "It's possible that maybe they were looking for such information" about the Clinton campaign.
"They wanted it so badly," she added.
Trump Jr. said he did not tell his father about the meeting. "There was nothing to tell," he said on Fox News.
'Potentially treason'
The New York Times reported that Paul Manafort and Jared Kushner, two of Trump's most trusted campaign officials, also attended the meeting with Veselnitskaya and Donald Jr last year.
The Kremlin has said it "did not know who" Veselnitskaya was.
"We can't be aware of all the meetings Russian lawyers have abroad," said spokesman Dmitry Peskov.
A spokesman for Kushner did not respond to request for comment.
Clinton's vice presidential running mate Tim Kaine described the revelations as moving toward more serious charges of perjury and "potentially treason."
"This should have set off alarm bells and red lights and instead, what it seemed to do is it activated their salivary glands," Kaine said in a separate interview with MSNBC.
"They should have turned this over to law enforcement immediately."
A senior White House official denied that there was anything inappropriate about the meeting with Veselnitskaya -- and said Trump was under no obligation to have disclosed it earlier.
"Who did this woman work for at the time? She did not work for the Russian government. …There was no connection (to the Kremlin)," Sebastian Gorka told CNN.
"She was a private lawyer who had an interest with regard to the Russian adoption program, and used a pretext to get a meeting with the campaign which the campaign representatives almost immediately realized was not done in good faith, that she had another agenda.
Gorka said Donald Jr had "no need" to disclose the meeting sooner, adding: "He's not a member of the administration."