The International Association of Machinists and Aerospace Workers union members in Missouri and Illinois rejected a modified contract offered by Boeing last week.

NEW YORK (AP) — Boeing workers who build fighter jets are planning to go on strike Monday at midnight.

(Reuters) -Union members who assemble Boeing's fighter jets in the St. Louis area rejected the U.S. planemaker's latest contract offer on Sunday and will strike at midnight on Monday, the International Association of Machinists and Aerospace Workers union (IAM) said.