Grassley said the committee would call Manafort to testify to learn why he didn't file as a foreign agent before becoming involved in the us presidential campaign.
Also in the room were Jared Kushner, the president's son-in-law, and the Trump campaign's then-chairman Paul Manafort, and a man accompanying Veselnitskaya whom NBC News reported was a former Soviet counterintelligence official with dual us and Russian citizenship.
Veselnitskaya confirmed to CNN and MSNBC that Kushner attended the meeting but said he was there for only "seven to 10 minutes" and she had never meant to hand over damaging information about Clinton anyway.
Manafort disclosed the meeting in a package of information he provided to the Senate and House intelligence committees, who have been investigating allegations of potential coordination between Russian Federation and the Trump campaign, as is Robert Mueller, the former Federal Bureau of Investigation director appointed by the Justice Department as the special counsel.
Trump Jr. - in his interview with Hannity - said that he is willing to testify under oath about the meeting.
Feinstein's office confirmed they were going to ask him. He said he showed up in jeans and a T-shirt.
"I know of no Russian gun-for-hire who managed to run his campaigns so successfully, running circles around purportedly much more seasoned Washington hands", veteran reporter Steve LeVine told Radio Free Europe in June 2016. "It's called opposition research, or even research into your opponent", Mr Trump said.
The committee is writing to Trump Jr. "That's very standard in politics; politics is not the nicest business in the world but it's very standard where they have information and you take the information", Trump said as he stood alongside French President Emmanuel Macron at a Paris news conference.
Akhmetshin said he does not know if Veselnitskaya's documents were provided by the Russian government. She suggested the Trump associates make them public.
It's unclear whether Trump Jr. would be as eager to testify before the Judiciary panel, which generally conducts open hearings.
One unnamed source with knowledge of the probe said it was unlikely that Russian operatives would have known "where to specifically target" key voters.
Then, when additional reporting backs up the story, the Trump administration backpedals, insisting that while some version of the events in question might have in fact occurred, there's no proof of collusion.
The civil forfeiture case was filed in 2013 by Preet Bharara, the former U.S. Attorney for the Southern District of NY - who was sacked by Trump in March. Veselnitskaya has denied having any ties to the Russian government.
CNN has reached out to the White House for comment. She did not respond to additional attempts to contact her Friday.
According to The Washington Post, Kushner-at a December 2016 meeting with Kislyak-raised the possibility of setting up a secret and secure communications link between the Trump transition team and the Kremlin.
"I never thought this would be such a big deal to be honest", the AP quotes Akhmetshin.
Human rights organizations believe that Russian authorities beat him and allowed him to die in prison so as to cover up government crimes. He also denied ever serving as a Russian counterintelligence officer, as he has been described in some media reports.