CHICAGO (NewsNation Now) — U.S. Senator Chuck Grassley (R-Iowa) announced Tuesday he has tested positive for the coronavirus and will quarantine.

Grassley, 87, made the announcement on Twitter.

“I’ve tested positive for coronavirus. I’ll b following my doctors’ orders/CDC guidelines & continue to quarantine. I’m feeling good + will keep up on my work for the ppl of Iowa from home. I appreciate everyone’s well wishes + prayers &look fwd to resuming my normal schedule soon”

Grassley is president pro tempore of the Senate and is the most senior Republican in the chamber. He has served as one of Iowa’s U.S. senators since 1981.

Grassley announced earlier Tuesday that he had been exposed to the virus and would quarantine immediately.

“I learned today that I’ve been exposed to the coronavirus. I will follow my doctors’ orders and immediately quarantine as I await my test results,” Grassley wrote. “I’m feeling well and not currently experiencing any symptoms, but it’s important we all follow public health guidelines to keep each other healthy.”