New documents released by US Senate offer new window into 2016 meeting with Russians close to the Kremlin.
The Senate Judiciary Committee released thousands of pages of documents on a Trump Tower meeting between members of the incoming US administration and Russian officials.
The congressional testimony, totalling 1,800 pages, provided rare insight on Wednesday into the June 9, 2016, meeting attended by Donald Trump Jr and the US president's former campaign chairman, Paul Manafort.
Senior adviser Jared Kushner, Trump's son-in-law, also partook in a meeting with Russian lawyer Natalia Veselnitskaya, who has close ties to the Kremlin.
Trump Jr admitted in testimony to Congress to seeking to obtain compromising material on then-Democratic Party frontrunner Hillary Clinton.
The meeting sparked a media storm and became of keen interest to investigators probing alleged Russian meddling in the 2016 presidential election.
The 40-year-old son of the president told Congress he does not remember informing his father of the meeting before it was reported by The New York Times a year later.
"Obviously he's aware of it now because he's read it, it's been in the papers, but that's the extent of my knowledge of his knowledge of it," he said.
Pressed to give further information as to whether he told his father immediately after the meeting, Trump Jr insisted he did not. "I wouldn't have wasted his time with it."
Steve Bannon, the president's former chief strategist, has said he believes the elder Trump likely knew of the meeting.
While Trump Jr has consistently maintained he did not tell his father of the meeting, a phone call with a blocked number suspected to be his father's has raised a number of questions.
On June 6, Trump Jr phoned Emin Agalarov, a Russian pop star and the son of an oligarch with close ties to President Vladimir Putin, who is said to have helped organise the meeting. Minutes later he called the blocked number.
Trump Jr then called Agalarov again. This time, the call lasted three minutes.
Corey Lewandowski, a former Trump campaign manager, told investigators Trump's "primary residence has a blocked [phone] line".
Investigators: Does your father use a blocked number on his mobile phone or on any phones that you call him on?
Trump Jr: I don't know.
Investigators: So you don't know whether this might have been your father?
Trump Jr was eager to find material that could be used to tarnish his father's political rival, Clinton.
Asked whether he was looking for potential information incriminating her, Trump Jr responded "yes", adding he didn't think "listening to someone with information relevant to the fitness and character of a presidential candidate would be an issue".
Following the publication of the Times report last year, Trump Jr downplayed the significance of the information offered.
"Her [Veselnitskaya's] statements were vague, ambiguous and made no sense. No details or supporting information was provided or even offered. It quickly became clear that she had no meaningful information," Trump Jr said in a statement at the time.
Recent revelations show Manafort was so unimpressed with Veselnitskaya’s presentation that he is said to have spent much of the meeting fidgeting with his phone, the Russian lawyer's translator, Anatoli Samochornov, said.
Neither was Veselnitskaya satisfied with her hosts' absent-mindedness.
"I know she was expecting something else from the meeting, something bigger," her translator added.
Meeting attendees confirmed in their testimony the meeting failed to offer anything substantial.
Rob Goldstone, a music promoter who acted as an intermediary between Trump Jr and the Russians, said no damaging information was presented to the campaign team.
"I don't know what would be deemed 'damaging', but I didn't hear anything that I would deem to be damaging … and I didn't see anybody react in a way that I believed people would react if they heard damaging information," he said.
"All else being equal, I wouldn't have wanted to waste 20 minutes hearing about something that I wasn't supposed to be meeting about," he said.
A single page of notes taken during the meeting by Manafort shows 11 bullet points, the meanings of which so far remain unknown.
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