President Donald Trump said Tuesday that the United States had killed the "number one replacement" to the Islamic State militant group's leader Abu Bakr al-Baghdadi, who was killed in a U.S. raid over the weekend.

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

Trump was speaking about the death of ISIS spokesman Abu Hassan al-Muhajir, a U.S. official confirmed to NBC News on Tuesday. A senior State Department official confirmed Monday that Muhajir had been killed in Syria during an operation by U.S. forces in which the Syrian Democratic Forces also played a large role. Muhajir's death was earlier announced by SDF commander Gen. Mazloum Abdi.

The tweet followed Trump's announcement Sunday morning of al-Baghdadi's death. The ISIS leader was the world's most-wanted terrorist. In his announcement, Trump provided sensitive details of the raid and intimate information regarding al-Baghdadi's death.