US Representative Maxine Waters (D-CA) looks on before speaking to reports regarding the Russia investigation on Capitol Hill in Washington, DC on January 9, 2018.
CNN  — 

House Financial Services Chair Maxine Waters says her committee is in talks with Treasury Secretary Steven Mnuchin to bring him in to testify on the lifting of Russia sanctions on companies connected to Russian oligarch Oleg Deripaska.

Waters said Wednesday that Treasury has not responded to a request for documents tied to the sanctions relief, but she hoped that she would be able to have Mnuchin appear before her committee soon.

“The delisting of Deripaska was never really debated, so we’re going to go after that as soon as we can get Mnuchin in,” Waters told reporters. “What we’re going to do is we’re going to get Mr. Mnuchin into the committee and ask him real pointed questions about delisting.”

A Treasury spokesperson could not be immediately reached for comment.

RELATED: Treasury spars with House Democrats over Mnuchin conflict of interest allegations

In December, Treasury announced it was lifting sanctions on three companies tied to Deripaska after he reduced his stake below 50%: aluminum giant Rusal, its holding company EN+ Group and subsidiary ESE.

Lawmakers balked at the move, and the House overwhelmingly voted to oppose the sanctions relief. But the Senate blocked the effort and the sanctions were lifted last week. Still, lawmakers like Waters have vowed to further investigate the implications of the deal.

Democrats have criticized the sanctions deal, arguing that Deripaska still retains “significant influence, if not de facto control, over EN+, Rusal and ESE” through his associates and family members. Last week, a number of Democrats sent letters to Mnuchin, perhaps the most pointed being from Rep. Jackie Speier of California.

In her letter, Speier questioned Mnuchin over his business ties with a Russian businessman who benefited from Treasury lifting sanctions on the companies.

The Treasury Department sharply disputed those conflict of interest claims.

Last week, Waters and two other committee chairmen sent Mnuchin a letter requesting documents on the decision to provide sanctions relief, with a deadline that was on Tuesday.

The letters to Mnuchin came less then two weeks after a hostile briefing with House Democrats on Capitol Hill, which Speaker Nancy Pelosi described a classified briefing on the plan to relax Russian sanctions as a “waste of time.”

CNN’s Donna Borak contributed to this report.