“Pratt & Whitney is a powerhouse in military and commercial aerospace products because our membership makes it so,” David Sullivan, the union’s eastern territory vice president, said in a statement. “This offer does not address the membership concerns, and the membership made their decision—we will continue to fight for a fair contract.”

Some workers are concerned that the company may move jobs and manufacturing out of the state to its plants in Georgia.

The company called its latest wage and retirement proposal competitive, and said its workforce is among the most highly compensated in the region and industry.

“Our message to union leaders throughout this thoughtful process has been simple: higher pay, better retirement savings, more days off and more flexibility,” the company said in a statement. “We have no immediate plans to resume negotiations at this time, and we have contingency plans in place to maintain operations and to meet our customer commitments.”

The strike comes as RTX, Pratt & Whitney’s parent company, faces a potential $850 million hit on profits this year because of tariffs imposed by President Donald Trump.

The company said its latest contract proposal included an immediate 4 percent wage increase, followed by a 3.5 percent increase in 2026 and a 3 percent increase in 2027. It also included a $5,000 contract ratification bonus and enhanced pension and 401k plan benefits.