Top US officials being interviewed for interim FBI director Attorney General Sessions and the deputy AG are interviewing candidates.

 -- U.S. Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein are interviewing candidates to take over the FBI as interim director, after James Comey's firing Tuesday.

Four candidates are being interviewed today, fielded from senior FBI and Justice Department officials and the heads of FBI field offices across the country, according to a Justice Department official.

The four candidates: FBI Executive Assistant Director Paul Abbate, who leads the agency’s cyber and criminal branch; National Counterintelligence Executive William Evanina; Special Agent Adam Lee, who runs the Richmond field office; and Special Agent Michael Anderson, who runs the Chicago field office.

A new FBI director is expected to be chosen and announced within the next 24 to 48 hours.

"The president is in the process of evaluating individuals who will be able to fill that spot, lead the FBI and restore the confidence in the American people,” Vice President Mike Pence said today on Capitol Hill.

In addition to a statement announcing the resignation, the White House released a letter Tuesday that Trump wrote directly to Comey dismissing him at the recommendation of the attorney general and the deputy attorney general, "effective immediately."

"While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgment of the Department of Justice that you are not able to effectively lead the Bureau," Trump wrote.

"It is essential that we find new leadership for the FBI that restores public trust and confidence in its vital law enforcement mission."