NEW YORK (Reuters) - Marathon Petroleum has been unwilling to negotiate with union members at its Detroit refinery since more than 200 workers went on strike, Teamsters said on Thursday, adding that the industrial action could be extended to the largest U.S. independent refiner's other plants.

Around 200 workers at Marathon's Detroit refinery walked off the job on Wednesday after months of pay- and safety-related negotiations and mediation with Marathon did not yield results.

"We want to go back to the table but they are refusing to bargain," said Steve Hicks, president of Teamsters Local 283.

Union members are fighting for higher pay, said Hicks. The wage increases Marathon offered to union members, around 3% each year, is not enough to keep up with inflation, Hicks said.

Members also want union security, he said. Michigan's repeal of its right-to-work law, which had prohibited workers paying union dues as a condition of employment in a unionized workplace, took effect in February.

Teamsters could extend the strike to other Marathon plants if negotiations continue to stagnate. "It's a big possibility," Hicks said.

The 140,000 barrel-per-day (bpd) Detroit refinery is one of Marathon's 13 refineries with approximately 2.9 million bpd of crude oil refining capacity.

Teamsters also represent workers at Marathon's 102,000-bpd Saint Paul refinery.

Marathon did not respond to requests for comment.