The House Foreign Affairs Committee says President Joe Biden's administration declined in a closed-door briefing to give details about why Robert Malley, the US special envoy for Iran, has been placed on leave.
“They refused to provide us any significant new information, including the reason his security clearance was revoked,” a committee representative told The National.
“We plan to follow up again to get actual information very soon.”
That would be the third attempt by the Republican-controlled committee to get answers from the administration over its placing of Mr Malley on leave pending a security clearance review.
“This is a person whose mission is to negotiate with the Islamic Republic of Iran – nothing could be more serious than this,” Mr McCaul had said.
The committee representative confirmed the closed-door meeting had taken place on Friday.
In a written response to Mr McCaul's first inquiry, the State Department said “the department is not in a position to provide further documents or information related to this personnel-security clearance matter”.
The letter, signed by assistant secretary for the Bureau of Legislative Affairs Naz Durakoglu, added that it was working on identifying “responsive information or records that may be appropriately provided to the committee given the sensitivity associated with that category of information”.
The House committee representative told The National the Biden administration had cited the Privacy Act in its tight-lipped response to questions over Mr Malley's leave.
The Privacy Act “prohibits the disclosure of a record about an individual from a system of records absent the written consent of the individual”, according to the Department of Justice, but has exceptions for disclosure, including to Congress.
The State Department declined to comment on the foreign affairs committee's characterisation of the meeting.
“Rob Malley remains on leave. We have nothing further to share at this time due to privacy considerations,” a department official told The National.