Robert Lorenzo Hester Jr., 28, of Columbia (Photo: Columbia Police)

A Missouri man who believed he was helping ISIS terrorists plot an attack on Kansas City was sentenced Wednesday to nearly 20 years in prison and a lifetime of probation.

Robert Lorenzo Hester Jr., 28, of Columbia, pleaded guilty in September to providing material support or resources to terrorists. Prosecutors said Hester gave materials such as nails and duct tape to people he believed were members of the ISIS but who were actually undercover federal agents.

Hester came to the attention of the FBI after posting several comments on social media supporting radical Islamic ideology and expressing hostility toward the US, according to federal prosecutors.

The FBI said Hester stated the US government should be "overthrown" and that the government should be hit "hard."

An FBI undercover officer told Hester the "attacks" were planned on buses, trains and a train station in Kansas City.

Hester was enlisted in the US Army for less than a year, receiving a general discharge from service in mid-2013.