The United States said it would offer up to $4 million for the arrest of a senior al-Qaeda leader who encouraged attacks against the country. The State Department on Thursday announced it would provide the reward in return for information on the further identification or location of Ibrahim Ahmed Mahmoud al-Qosi.

Al-Qosi is part of the leadership team that assists the current “emir” of the Al-Qaeda in the Arabian Peninsula (AQAP).

“Since 2015, he has appeared in AQAP recruiting materials and encouraged lone wolf attacks against the United States in online propaganda. He joined AQAP in 2014, but has been active in al-Qaeda for decades and worked directly for Osama bin Laden for many years,” the State Department said in a statement.

Al-Qosi was captured in Pakistan in December 2001 before being transferred to Guantanamo Bay, according to the statement.

He pleaded guilty in 2010 before a military commission to conspiring with al-Qaeda and providing material support to terrorism. However, he was released and returned to Sudan in 2012 pursuant to a pretrial agreement. The US often offers rewards in exchange for information on the whereabouts of terrorists that can range from $3 million to over $10 million.