"I read those emails. He only responded to two or three of them, and they were very innocuous," Grassley told CNN. "So I don't even know why you'd be asking about him if you read them."
Asked about a public hearing for Trump Jr. — which Democrats on the panel are calling for in the wake of the disclosure of the WikiLeaks emails Monday — Grassley said it was a matter he still had to discuss with California Sen. Dianne Feinstein, the top Democrat on the committee.
"We are not going to be making any decisions on that until we discuss it between the two of us," the Iowa Republican said.
Feinstein told reporters that she wants Trump Jr. to come in as soon as possible, and that she understands he has expressed a willingness to come before the committee. President Donald Trump's son appeared for a staff interview behind closed doors
earlier this year after his June 2016 meeting with a Russian lawyer was revealed.
"I am very hopeful we'll be able to have him before the committee as soon as possible," she said. "In view of everything that's come out — and also, as I understand it, he's willing to come — that it could get scheduled, and hopefully the chairman will do that."
Feinstein said she was also hopeful he would appear without a subpoena, something the committee has not ruled out to compel his testimony.
After the disclosure of the Twitter messages, frustration mounted among Democrats that Grassley has not yet scheduled a hearing with Trump Jr.
Democratic Sen. Dick Durbin of Illinois said the judiciary panel "has ceded its leadership on this important issue."
"We're supposed to be preparing the laws to avoid future occurrences like the Russian invasion of our election," Durbin said. "Unfortunately, with the exception of Sen. (Lindsey) Graham's subcommittee, almost nothing has been done by the full committee."
A Senate Democratic source said the committee is still moving toward a potential public hearing with Trump Jr., but wanted to get other interviews completed first.
The panel on Tuesday interviewed Russian-American lobbyist Rinat Akhmetshin — who was in the June 2016 meeting with Trump Jr. — another source said. Akmetshin declined to comment on the interview when he left the Capitol on Tuesday.