A former Illinois National Guard soldier pleaded guilty Monday to charges alleging he conspired to provide material support to the Islamic State group.

Hasan Edmonds, 23, of Aurora, Illinois, pleaded guilty to one count of conspiring to provide material support to a foreign terrorist organization and one count of attempting to provide material support to a foreign terrorist organization.

The pleas in Chicago federal court came one week after his cousin, Jonas Edmonds, 30, of Aurora, pleaded guilty to similar charges.

"Hasan and Jonas Edmonds conspired to provide material support to ISIL," John P. Carlin, assistant attorney general for national security, said in a news release, using one of the alternative names for the Islamic State group. "They admitted planning to wage violence on behalf of ISIL in the Middle East and to conduct an attack on our soil."

Prosecutors say Hasan Edmonds devised a plan for Hasan Edmonds to travel to the Middle East and join Islamic State fighters overseas. After dropping his cousin off at Midway International Airport last March, Jonas Edmonds went to Hasan Edmonds' home and collected several National Guard uniforms that he planned to wear as a disguise during a planned attack at the Joliet armory, the plea agreement said.

Agents with the Chicago FBI's Joint Terrorism Task Force arrested Hasan Edmonds before he could board his flight and arrested Jonas Edmonds at his home a short time later.

Charges alleged the armory attack was planned to kill as many as 150 people.

Hasan Edmonds is to be sentenced March 18 and faces up to 30 years in prison. Jonas Edmonds is to be sentenced Jan. 27 and faces up to 23 years in prison.