Donald Trump Jr. has agreed to conduct a transcribed interview with the Senate Judiciary Committee, something investigators have been seeking ever since President Trump's eldest son tweeted out an email chain detailing how he accepted an invitation to meet with a Russian lawyer who was promising damaging information on Hillary Clinton and her campaign.

The committee had invited him to testify in public in July, but Trump Jr. was able to negotiate the closed-door interview, confirmed by a spokesman for the committee and first reported by CNN. However, the spokesman would not confirm the exact date the interview will take place.

The committee's chairman, Sen. Chuck Grassley, R-Iowa, and ranking member, Sen. Dianne Feinstein, D-Calif., put out a statement later in the day, and they too did not confirm a date.

"In late July, Donald Trump Jr. agreed to provide the Judiciary Committee with documents and a transcribed interview prior to a public hearing. Shortly thereafter, a date for that interview was set and agreed to by both the Committee and Trump Jr," the senators wrote. "This meeting will be conducted under the same terms as previously announced."

In July, Trump Jr. tweeted the emails that detailed the meeting with a Russian lawyer and others in response to an imminent report from the New York Times, which was set to publish the email chain after it had already reported on the existence of the communications.

The evidence was one of the first hard connections between the Trump campaign and any Russian official, other than some occasional contacts with then-Russian Ambassador Sergey Kislyak, which those related to the Trump campaign have continued to maintain were incidental meetings.

Whether Trump Jr. will have to testify in any public setting is still yet to be seen.

Just after releasing the email chain, Trump Jr. went on Fox News with Sean Hannity and downplayed the importance of the emails, and told the host, "I think it's a little bit ridiculous and overplayed."

The meeting in Trump Tower with Russian lawyer Natalia Veselnitskaya was also attended by President Trump's son-in-law Jared Kushner, and then-campaign manager Paul Manafort.

Veselnitsaya has indicated she is willing to testify to a senate panel about the meeting as well.