Washington, May 21 (IANS): US Secretary of State Mike Pompeo has doubled down on his request for President Donald Trump to fire the State Department's Inspector General (IG) Steve Linick amid bipartisan scrutiny.

"I recommended to the President that Steve Linick be terminated. Frankly, should've done it some time ago," Pompeo told reporters during a briefing at the State Department on Wednesday.

Last week, Trump had announced that he was firing Linick because he did not have the fullest confidence in the official, who began his tenure as the State Department's watchdog in 2013.

The decision has sparked an inquiry by Democrats and scrutiny even from a number of Republicans, as Linick was reportedly looking into a number of issues related to Pompeo.

On Wednesday, Pompeo denied any knowledge of investigations being undertaken by Linick.

"I've seen the various stories that someone was walking my dog to sell arms to my dry cleaner, I mean, it's just crazy," he said, arguing that charges of political retaliation were "patently false".

House Speaker Nancy Pelosi said on Wednesday that Pompeo should testify before Congress.

"Let's see how this unfolds," the California Democrat told reporters on Capitol Hill.

"But what it is that we know so far is scandalous."

As IG, Linick was responsible for, among other things, conducting administrative and criminal investigations of waste, fraud, mismanagement, and misconduct in the State Department.

Besides Linick, Trump has moved in the past few weeks to fire Intelligence Community IG Michael Atkinson, acting Pentagon IG Glenn Fine, and Christi Grimm, principal deputy IG of the Department of Health and Human Services.