The House of Representatives will vote to formalize impeachment proceedings against President Trump, Nancy Pelosi announced in a letter Monday.

The inquiry into the president's July 25 phone call with Ukrainian President Volodymyr Zelensky is set for Thursday, senior House Democratic aides told NPR. The GOP has expressed frustration with Democrats for not holding such a vote.

The resolution, which will be introduced in the House Rules Committee, will be the first vote the House takes as a whole regarding the authorization of the proceedings.

"This week, we will bring a resolution to the Floor that affirms the ongoing, existing investigation that is currently being conducted by our committees as part of this impeachment inquiry, including all requests for documents, subpoenas for records, and testimony, and any other investigative steps previously taken or to be taken as part of this investigation," Pelosi's letter reads.

"The resolution establishes the procedure for hearings that are open to the American people, authorizes the disclosure of deposition transcripts, outlines procedures to transfer evidence to the Judiciary Committee as it considers potential articles of impeachment, and sets forth due process rights for the President and his Counsel," it continues.