The Islamic State's primary spokesman and reputed No. 2 in Syria has been killed in Aleppo, according to a news website affiliated with ISIS.

In a statement issued in both Arabic and English, the Amaq site says Abu Mohammed al-Adnani was conducting surveying operations around Aleppo when he was killed.

A Pentagon spokesman said that the U.S. conducted an airstrike earlier on Tuesday near al Bab, Syria, targeting an Islamic State senior leader, but did not confirm whether al-Adnani had been killed.

"Today coalition forces conducted a precision strike near Al Bab, Syria, targeting Abu Muhammad Al-Adnani, one of ISIL's most senior leaders. We are still assessing the results of the strike, but Al-Adnani's removal from the battlefield would mark another significant blow to ISIL," said Pentagon Press Secretary Peter Cook in a statement.

"Al-Adnani, has served as principal architect of ISIL's external operations and as ISIL's chief spokesman," Cook added. "He has coordinated the movement of ISIL fighters, directly encouraged lone-wolf attacks on civilians and members of the military and actively recruited new ISIL members. The U.S. military will continue to prioritize and relentlessly target ISIL leaders and external plotters in order to defend our homeland, our allies and our partners, while we continue to gather momentum in destroying ISIL's parent tumor in Iraq and Syria and combat its metastases around the world."

Another senior Pentagon official said that al-Adnani was "a legacy AQI member, a Shura council member, and the most publicly recognizable official in ISIL."

"If confirmed, this is a very significant blow for ISIL, and will degrade its ability to direct and inspire terror attacks on the West," the official said. The U.S. State Department designated al-Adnani as a "Specially Designated Global Terrorist," in 2014.

"Abu Mohammed al-Adnani, born Taha Sobhi Falaha in Syria, is the official spokesman for and a senior leader of ISIL," the department's website says. "Al-Adnani is ISIL's main conduit for the dissemination of official messages, including ISIL's declaration of the creation of an Islamic Caliphate. Al-Adnani was one of the first foreign fighters to oppose Coalition forces in Iraq before becoming ISIL's spokesman."

Current ISIS Territory Status in Iraq and Syria Graphiq