"This is the greatest Witch Hunt in political history. Sad!"
Trump has repeatedly referred to the investigations into Russian interference in the US election as a "witch hunt", arguing it is a politically motivated scheme to discredit his victory and justify Clinton's loss.
The President also took the opportunity to take a swipe at the journalists on Wednesday, as his war on the media continues to rage.
Remember, when you hear the words "sources say" from the Fake Media, often times those sources are made up and do not exist.
Donald Jr emphasised during the Fox News interview that his father knew nothing about the meeting, which was also attended by Trump's son-in-law Jared Kushner and his then campaign director Paul Manafort.
"For me this was opposition research. They had something, you know, maybe concrete evidence to all the stories I'd been hearing about, probably under-reported for years not just during the campaign so I think I wanted to hear it out," Donald Jr said.
"But really it went nowhere and it was apparent that wasn't what the meeting was about."
However, he added: "In retrospect I probably would have done things a little differently."
The White House is in damage control as more and more details have leaked out this week about how the June 2016 meeting at Trump Tower came about.
Donald Jr tweeted an email chain on Wednesday that revealed he was aware of a Russian government campaign to support Trump's bid for president.
"This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr Trump," British entertainment publicist Rob Goldstone emailed Donald Jr on June 3 to set up the meeting.
Russian lawyer Natalia Veselnitskaya met with Donald Trump Jr, Jared Kushner and Paul Manafort at Trump Tower. Photo / AP
Goldstone said his associates had information that "would incriminate" Clinton and "would be very useful to your father".
Donald Jr replied to the email four minutes later, expressing his delight at the prospect of information that would be harmful to his father's opponent.
"If it's what you say, I love it, especially later in the summer," Donald Jr replied, referring to a time closer to the election when it would have been most politically beneficial to drop damaging information about the Democratic presidential candidate.
Along with Trump, other sympathetic Republicans have praised Donald Jr for his "transparency" in publishing the email conversations.
However, The New York Times has revealed that Donald Jr released the emails on Twitter only after they had obtained them and notified him that they would be reporting on them.
Donald Jr's explanation has also changed significantly since the weekend, when he initially told the Times that the meeting was a "short introductory meeting" concerned with the ban on Americans adopting Russian children.
He said in a later statement that the lawyer, Natalia Veselnitskaya, told him during the meeting that Russian individuals were improperly funding the Democratic National Committee and supporting Clinton.
"Her statements were vague, ambiguous and made no sense," Donald Jr said in a statement to the Times on Sunday.
"No details or supporting information was provided or even offered.
"It quickly became clear that she had no meaningful information."
