Deputy Attorney General Rod Rosenstein said Thursday his exit from the Justice Department is coming "a lot later" than he expected amid reporting that special counsel Robert Mueller could wrap up the Russia investigation within a week.

Rosenstein made the comment during a speech to his alma mater, the Wharton School at the University of Pennsylvania, which he called "one of my last significant events" as the No. 2 law enforcement official in the nation.

“My time as a law enforcement official is coming to an end, a lot later than I expected," he said.

The speech comes one day after CNN reported Attorney General William Barr could announce as soon as early next week the end of Mueller's investigation into Russian interference in the 2016 election.

Rosenstein, who appointed Mueller to the special counsel role in May 2017 in the days after President Trump fired FBI Director James Comey, has overseen the day-to-day operations of the inquiry, which is also examining possible collusion between the 2016 Trump campaign and the Kremlin and whether the president attempted to obstruct justice.

A DOJ source told CNN on Sunday that Rosenstein plans to leave the department by mid-March, claiming that he always intended to leave after helping with the transition for his successor. In January, a DOJ source told the Washington Examiner that Rosenstein was expected to depart within weeks as he only always expected to serve for about two years.

In recent days, Trump has accused Rosenstein and former FBI Deputy Director Andrew McCabe of planning to carry out an "illegal and treasonous" plan against him.

McCabe, who is promoting his new book this week, provided the first on-the-record corroboration of months-old reports that Rosenstein told Justice Department officials about wearing a “wire” to record conversations with Trump and that he had discussed invoking the 25th Amendment against the president to remove him from office in the days after Comey was fired.

The Justice Department claims his version of events was "inaccurate and factually incorrect" and that Rosenstein never authorized the use of a wire to secretly record Trump.