Putin critic says Russian lawyer's Trump Tower meeting was about sanctions Bill Browder appeared before the Senate Judiciary committee Thursday.

 -- The Russian lawyer who met with Donald Trump Jr., Jared Kushner and Paul Manafort in Trump Tower is the Russian government's "point person" in fighting U.S. sanctions and took the meeting to discus sanctions relief, a prominent Putin critic told Congress Thursday.

Bill Browder, an American-born financier who worked extensively in Russia, appeared before the Senate Judiciary committee Thursday. He's emerged as a prominent critic of Russian President Vladimir Putin after the death of his former attorney Sergei Magnitsky.

Magnitsky, who died in a Russian jail after accusing Russian government officials of stealing millions of dollars in a tax fraud scheme, is the namesake of the Magnitsky Act sanctions law against human rights violations passed by Congress.

Browder told the panel he has "no doubt" the controversial meeting in Trump Tower in June of 2016 was orchestrated by the Kremlin.

"The interest and the goal in that meeting was to repeal the Magnitsky Act," Browder said. "That's the one thing we can conclude with certainty about what happened in that meeting."

While emails released by President Trump's eldest son indicate that the meeting was arranged after Trump Jr. was promised compromising information on Hillary Clinton, Veselnitskaya told ABC News she attended the meeting to discuss the Magnitsky Act and Russian adoptions.

Kushner and the White House have both said the meeting was about adoptions.

Browder told senators Thursday that the ban on Americans adopting Russians was "retaliation" from Russia after the passage of the Magnitsky Act, and that any conversation about adoptions was tied to sanctions.

"This was a big ask, to go and ask the possible future next president of the United States to repeal a major piece of human rights legislation, they wouldn't have gone in and said please can you repeal this for us without having something to offer in return," he said of the meeting.

Democrats and Republicans in attendance Thursday vowed to keep the existing sanctions in place.

"There is no way that Congress would agree to repeal the Magnitsky Act," Sen. John Cornyn, R-Texas, said.

Browder faced Congress alone Thursday, though the committee had initially invited Manafort and Trump Jr. to appear to discuss their meeting. Both are cooperating with the committee's investigation under threat of subpoena - which Sens. Grassley and Feinstein issued, and later withdrew, for Manafort.

He also testified that opposition research firm Fusion GPS, which funded research for the dossier of unverified allegations against President Trump, also worked separately to lobby against the Magniskty Act.