A senior commander in Syria's rebranded Al Qaeda affiliate, who was close to the global network's top leader Ayman al-Zawahri, was targeted in an airstrike Monday, according to the Pentagon.

U.S. forces targeted Egyptian national Abu al-Farai al-Masri, also known as Ahmad Salamah Mabruk, in an airstrike near Idlib, Syria, Pentagon Press Secretary Peter Cook said in a statement.

"We are still assessing the results of the strike," he said.

Mabruk was a legacy Al Qaeda terrorist who previously had ties to Usama bin Laden.

While the Pentagon would not yet say if he was killed, the Fatah al-Sham Front, previously known as the Nusra Front, announced the death on its Twitter account.

The Britain-based Syrian Observatory for Human Rights, which relies on a network of activists inside Syria, said Mabruk was killed when his vehicle was struck near the border with Turkey.

Another senior commander from the group, Abu Omar Saraqib, was killed in an airstrike last month.

Mabruk was imprisoned in his native Egypt in 1981 in the sweep following the assassination of President Anwar Sadat. He later traveled to Afghanistan, where he became close to al-Zawahri before traveling to Syria earlier this year.

Fatah al-Sham recently announced it was changing its name and severing ties with al-Qaida in a video in which Mabruk sat next to the group's top leader, Abu Mohammed al-Golani.

Due to of the presence of Al Qaeda veterans like Mabruk among its ranks, most experts still view the group as an Al Qaeda affiliate, and both the United States and Russia have vowed to keep striking it.

Fox News' Lucas Tomlinson and the Associated Press contributed to this report.