While the committee has not confirmed that they have invited or plan to invite Trump Jr.to testify, Sen. "I think it's been lackadaisical enforcement, and he would be an example of that lackadaisical enforcement".
"It was in black and white that it was part of a Russian government effort to help Trump discredit Clinton", Sen.
Just weeks ago, Manafort retroactively registered with the Department of Justice as a foreign agent after being paid more than $17 million overseas.
On Tuesday, Trump Jr. told Fox News' Sean Hannity: "In retrospect, I probably would have done things a little differently", but added that the meeting came before Russian involvement becoming a major story during the campaign season.
Members of the House Intelligence Committee, which is investigating Russian meddling in the U.S. election, said they would also like to hear from Mr Trump Jr.More news: Both 2024 and 2028 Olympics to Be Decided in September
The chairman noted that the committee is holding hearings next week on the Federal Agent Registration Act, which requires Americans to register to work as lobbyists of foreign governments.
"It is unclear how she was still in the country for that meeting despite being denied a visa beforehand and her parole purportedly expiring on January 7, 2016".
Grassley is now asking how it was possible for Veselnitskaya to enter the United States for the meeting without a visa.
"Obviously it would be appropriate for anybody to get into anything that went on at that meeting, and he was at that meeting", Grassley told Iowa reporters.More news: Mithali Raj becomes highest run scorer in ODI
Grassley lead the hearing as committee chairman, starting off with an opening statement that detailed job duties of the Federal Bureau of Investigation director and Wray's credentials.
Grassley said there will be a hearing within days on the lax enforcement.
Although he's entangled in the larger web created by the Russian Federation probes, Manafort previously disclosed this meeting to congressional investigators before Trump Jr. leaked his emails - but he wasn't required to disclose the content of it.More news: Lena Headey from Game of Thrones Opens Up About Postpartum Depression