White House press secretary Sarah Sanders said Thursday that President Trump is criticizing only FBI leadership when he says the bureau's reputation is "in tatters."

"The president is referring to the political leaders at the FBI, particularly those that were involved in the Hillary Clinton probe," Sanders said at the daily White House press briefing.

Trump tweeted Sunday: "After years of Comey, with the phony and dishonest Clinton investigation (and more), running the FBI, its reputation is in Tatters - worst in History! But fear not, we will bring it back to greatness."

Sanders gave the clarification amid a marathon Capitol Hill hearing with FBI Director Christopher Wray, where many Democrats said Trump's remark was an attack on the bureau's entire workforce.

Rep. Ted Lieu, D-Calif., said at the hearing the "earlier this week the president of the United States attacked the dedication and integrity of 37,000 FBI employees. I believe that's outrageous."

Republicans at the hearing, meanwhile, grilled Wray on revelations that senior FBI official Peter Strzok was reassigned over the summer after demonstrating a pro-Hillary Clinton, anti-Trump bias in text messages to his mistress, another FBI employee.

Before being reassigned, Strzok was a member of special counsel Robert Mueller's probe of possible Trump links to Russia. And before that, Strzok was influential in the FBI's probe of Hillary Clinton's use of a private email server as secretary of state.

Strzok reportedly signed papers opening the Russia probe and oversaw an interview with former Trump adviser Michael Flynn, who pleaded guilty last week to lying to FBI agents. He also reportedly changed the wording in a preemptive FBI exoneration of Hillary Clinton from "grossly negligent" to "extremely careless" and attended the subsequent interview with Clinton.

Strzok's conduct is being reviewed by the Justice Department's inspector general, and Wray declined to comment on many details when pressed by lawmakers, citing that review.

"We agree with Chris Wray that FBI field agents are appreciated and respected," Sanders said at the White House press briefing. "The president's issues are with the political leaders under former FBI Director Comey who played politics with the Clinton probe."

Trump fired Wray's predecessor James Comey in May. The Senate confirmed Wray to a 10-year term in August.

Later in the press briefing, Sanders added: "We're glad Director Wray is there, we feel like he's going to clean up some of the messes left by his predecessor."