WASHINGTON (Reuters) - The United States on Tuesday offered a reward of up to $3 million for information about a former Tajik special operations colonel whom it trained in counter-terrorism before he joined the Islamic State militant group.

The U.S. State Department announced the reward for Gulmurod Khalimov in a statement that made no mention of his training, which included attending five U.S.-funded courses in the United States and Tajikistan between 2003 and 2014, said a U.S. State Department official who spoke on condition of anonymity.

The statement described Khalimov as “a key leader” of the Islamic State militant group, also known as ISIL and ISIS, that has seized parts of Syria and Iran and staged or inspired attacks around the world.

“Khalimov is a former Tajik special operations colonel, police commander, and military sniper. He was the commander of a police special operations unit in the Ministry of Interior of Tajikistan. He is now an ISIL member and recruiter,” it said.

“In May 2015, he announced in a 10-minute propaganda video that he fights for ISIL and has called publicly for violent acts against the United States, Russia, and Tajikistan,” it added.

The State Department’s “Rewards for Justice” program, which has also targeted Osama bin Laden and former Iraqi dictator Saddam Hussein, offered up to $3 million for information leading to Khalimov’s location, arrest or conviction.

The State Department official who spoke on condition of anonymity suggested that Khalimov was regarded as a special threat because of his counter-terrorism training, which included “crisis response, hostage negotiation and tactical leadership.”

“We consider Gulmurod Khalimov to be a threat to national security and the U.S. Department of State due to his prior counter-terrorism experience and training,” the official said.

The official declined to say exactly how many courses Khalimov attended in the United States and where they took place or to shed further light on his evolution from a counter-terrorism commander to an Islamic State leader.

The training was provided under the State Department’s anti-terrorism assistance program, the official said.