Wisconsin Gov. Scott Walker said he has ruled out a 2020 presidential run.

"I'm ready to run for governor in 2018. I'm going to fill my term out for the next four years," he told CNBC on Tuesday.

Walker ran for the Republican nomination for 2016 against a vast array of candidates. He suspended his campaign in September 2015, one of the earliest big-name politicians to drop out.

Walker was elected governor in 2010, kept the job after a recall election in 2012, and was re-elected in 2014.

Under Wisconsin's constitution, there is no term limit for the governorship.