What Donald Trump Jr. told Senate investigators today about his meeting with a Russian lawyer Investigators said questions remain.

 -- After a five-hour meeting with congressional investigators, Donald Trump Jr. said he felt his interview "fully satisfied their inquiry,” but Democratic lawmakers tell ABC News he didn’t come close.

"There are gaps in the information we have today that we need to fill. And he was unable to answer a lot of those questions for whatever reason and we need to continue to explore them and seek answers,” Sen. Richard Blumenthal, D-Conn., who sat in for most of the interview, told ABC News.

While the bulk of today’s interview centered on Trump Jr.'s meeting with a Russian lawyer and others in Trump Tower during his father's presidential campaign, investigators said questions remain.

Sources told ABC News that Trump Jr. told investigators that he did not tell his father about that June 2016 meeting and said he didn't introduce any of the meeting participants to his father while they were at Trump Tower. It’s unclear if his father ever found out about the meeting before The New York Times reported on it.

Investigators are also curious to learn more about the president’s role in crafting the White House response when news of the meeting broke. It was previously reported that President Donald Trump personally dictated the first statement his son gave in response to questions about the June 2016 meeting.

Sources said Thursday the president’s son today tried to distance himself from the White House response and his father’s involvement.

Sources also said Trump Jr. fielded a lot of questions about the structure and financial dealings of the Trump Organization.

Members of the committee said today’s interview, which was conducted by staff, is just a jumping-off point.

“It frankly raised more questions for me than it answered,” Sen. Chris Coons, D-Del., told ABC News. “And I am very much looking forward to having him in front of us on the Judiciary Committee under oath, on television, answering questions that I think the American people need to hear answered.”

Coons is confident that “one way or another” Trump Jr. will testify publicly, saying they will issue a subpoena if necessary.

“I don't think Donald Trump Jr. will be able to avoid the public eye much longer,” he said.

ABC News' Ali Rogin contributed to this report.