Boeing's defence operations faced disruptions on Monday as thousands of union workers went on strike, halting assembly lines for fighter jets and missile systems. The strike began after members of the International Association of Machinists and Aerospace Workers (IAM) District 837 overwhelmingly rejected Boeing's latest contract offer.

Several thousand workers at three Midwest manufacturing plants where Boeing develops military aircraft and weapons went on strike early Monday, potentially complicating the aerospace company's progress in regaining its financial footing.

Roughly 3,200 workers are striking at sites in Missouri and Illinois. Members of the labor union representing the workers rejected a modified contract offered by Boeing last week.