Oklahoma Sen. Jim Inhofe, a leading conservative Republican and veteran of the Senate, is expected to announce in the coming days that he will cut short his six-year term and retire near the end of 2022, according to a person familiar with the matter.

Inhofe, 87, is a defense hawk who serves as the top Republican on the Senate Armed Services Committee. He is also a former chairman of the Senate Environment and Public Works Committee, where he drew the ire of environmentalists over his denunciations of climate change as a “hoax.”

Inhofe, whose Senate career started after his 1994 victory, won reelection as recently as