State Department Inspector General Steve Linick has requested to meet Wednesday with a number of Senate and House committees "to discuss and provide staff with copies of documents related to the State Department and Ukraine," according to a letter first reported by the Washington Post.

Why it matters: The details of the "urgent" briefing are unknown, but the news follows an escalating war of words between Secretary of State Mike Pompeo and key House committees investigating President Trump's alleged efforts to pressure Ukraine to investigate Joe Biden.

On Tuesday, the chairs of the House Intelligence, Foreign Affairs and Oversight committees rebuked Pompeo for attempting to block State Department officials from testifying, accusing him of "stonewalling."

The Wall Street Journal and others reported on Monday that Pompeo was on the now-infamous phone call between Trump and Ukraine's president, leading the committees to label Pompeo a "fact witness" in their impeachment investigation.

Former U.S. special envoy to Ukraine Kurt Volker, who resigned last week, confirmed Tuesday that he would appear for a deposition before the committees later this week. 4 other current or former State Department officials are scheduled to testify in the next 2 weeks, but they have not yet confirmed.

According to CNN's Manu Raju, the inspector general will meet with the following committees:

House Foreign Affairs

Senate Foreign Relations

House Appropriations

Senate Appropriations

House Oversight

Senate Homeland Security

House Intelligence

Senate Intelligence

Go deeper: House chairmen accuse Pompeo of "stonewalling" in Ukraine investigation