Unionized workers at Samsung Electronics declared an indefinite strike Wednesday to pressure South Korea’s biggest company to accept their calls for higher pay and other benefits.

Thousands of members of the National Samsung Electronics Union launched a temporary, three-day strike on Monday. But the union said Wednesday that it was announcing an indefinite strike, accusing the management of being unwilling to negotiate. Samsung Electronics says there have been no disruptions to production.

"Samsung Electronics will ensure no disruptions occur in the production lines," a Samsung statement said. "The company remains committed to engaging in good faith negotiations with the union."

However, in a statement posted on its website, the union said it has engaged in unspecified disruptions on the company’s production lines to get management to eventually come to the negotiating table if the strikes continue.

"We are confident of our victory," the union statement said.

The union statement didn’t say how many of its members would join the extended strike. It earlier said that 6,540 of its union members had said they would participate in the earlier, three-day strike.

That would represent only a fraction of Samsung Electronics’ total workforce, estimated at about 267,860 globally. About 120,000 of them are in South Korea.

Earlier this year, union members and management held rounds of talks on the union's demand for higher wages and better working conditions, but they failed to reach agreement. In June, some union members collectively used their annual leaves in a one-day walkout that observers said was the first labor strike at Samsung Electronics.

About 30,000 Samsung workers are reportedly affiliated with the National Samsung Electronics Union, the largest at the company and some belong to other, smaller unions.

In 2020, Samsung chief Lee Yong, then vice chairman of the company, said he would stop suppressing employee attempts to organize unions. He expressed remorse over his alleged involvement in a massive 2016 corruption scandal that removed the country’s president from office.

The company’s union-busting practices had been criticized by activists for decades, though labor actions at other businesses and in other sectors of society are common in South Korea.

Thousands of South Korean medical interns and residents have been on strike since February, protesting a government plan to sharply increase medical school admissions.