(Reuters) -Top machinists union officials and a Democratic congressman joined striking workers outside a Boeing Defense facility near St. Louis on Thursday, pressing the company for a contract closer to an agreement reached with its Seattle-area workers.

However, Boeing's top St. Louis executive, Dan Gillian, on Thursday defended the company's offer that was rejected by the 3,200 members of the International Association of Machinists and Aerospace Workers (IAM) District 837.

The workers went on strike on August 4, shutting down production of the F-15 and F/A-18 fighters.

"Our offer was strong then and is strong now with an average of 40% wage growth," Gillian said in a statement on Thursday. 

There currently is no plan to resume negotiations, officials on both sides said. 

"The IAM is ready to meet with Boeing," IAM International President Brian Bryant told Reuters.

Bryant was among the union leaders who joined the striking workers in picketing, along with U.S. Rep. Wesley Bell, a Missouri Democrat, who represents the area.

Workers want a contract offer with higher general wage increases, to speed up how long it takes to reach the top of the wage scale, and improvements to the company's 401(k) retirement plan, Bryant said.

"In reality, they're going to have to offer up the same thing they offered in Seattle," he said, referring to a four-year contract approved in November by the roughly 33,000 members of the IAM District 751, who assemble most of Boeing's jetliners in the Northwest.

That contract included a 38% general wage increase over four years, plus higher retirement plan contributions, restoration of an annual bonus, a $12,000 signing bonus, and a pledge to build Boeing's next commercial jet in the Seattle area, if the program is launched within the contract's duration.

The offer rejected by St. Louis-area workers included a 20% general wage increase, a $5,000 ratification bonus and more vacation time and sick leave.