Mueller cleared Trump Jr., Manafort to testify publicly on meeting with Russian attorney: Feinstein

— -- Donald Trump Jr. and Paul Manafort have been cleared by special counsel Robert Mueller to testify in an open session before the Senate Judiciary Committee about their June 2016 meeting in Trump Tower with a Russian attorney, according to the committee's ranking member Sen. Dianne Feinstein, D-Calif.

Feinstein, who met with Mueller last month, shared the information with reporters Tuesday, later adding that the special counsel's investigation would "not be a problem" that would prevent their testimony. The news of the pair's clearance to be interviewed was first reported by CNN.

The Judiciary Committee was scheduled to hold a hearing on the Foreign Agent Registration Act Wednesday, one at which Committee Chairman Chuck Grassley, R-Iowa, said he wanted Manafort to appear. Both he and Feinstein also suggested Trump Jr. should appear before the committee this week.

Grassley postponed the hearing Tuesday afternoon. Grassley's office did not respond to ABC News' questions about possible changes to Wednesday's hearing or contact with Manafort and Trump Jr., who weren't scheduled to appear, prior to word of its postponement. Feinstein declined to say whether the committee has contacted Manafort.

A source with direct knowledge told ABC News that Manafort -- who was previously contacted by the Senate Intelligence Committee -- is not committed to an appearance before the Judiciary Committee. The source added that Manafort is not certain which committee he will cooperate with or in what order.

The source added that Manafort does not have his campaign emails, which hinders his ability to prepare for questions from any congressional committees.

As ABC News has previously reported, Manafort has been cooperating with congressional investigators and turned over documents they requested. At no point was Manafort subpoenaed for information.