The likely successor to the now-dead Abu Bakr al-Baghdadi is also dead, President Trump tweeted Tuesday morning. According to the president, the unidentified "number one replacement has been terminated by American troops."

"Just confirmed that Abu Bakr al-Baghdadi's number one replacement has been terminated by American troops. Most likely would have taken the top spot - Now he is also Dead!" the president tweeted.

The White House did not immediately clarify which ISIS leader the president was referencing. But a State Department official confirmed Monday that a strike did kill ISIS spokesman Abu al-Hassan al-Muhajir in a strike on Sunday, CBS News Pentagon correspondent David Martin reports.

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Mr. Trump has taken pride in the death of al-Baghdadi, which he alluded to in a cryptic tweet Saturday night before making a formal announcement from the White House's Diplomatic Room Sunday morning. On Monday, the president continued to highlight al-Baghdadi's death as a mark of the United States' success against ISIS.

"He was a sick and depraved man and now he's dead," Mr. Trump told police chiefs during a speech in Chicago. "He's dead, he's dead as a doornail. And he didn't die bravely either, I will tell you that. He should have been killed years ago. Another president should have gotten him.

"But to me it was very important, I would say all the time, they would walk into my office, 'sir we killed this leader at a level, this leader at-' I said I never heard of him, I want al-Baghdadi, that's the only one I know now, I want al-Baghdadi, get him, and they got him."

The Pentagon is expected to release video of the raid that killed al-Baghdadi.