Mexico’s top trade negotiator, who was overseeing an ongoing dispute with the US over President Andres Manuel Lopez Obrador’s energy policy, was pushed out of her job by the country’s new economy chief, according to people familiar with the matter.

Luz Maria de la Mora, Mexico’s undersecretary of the economy for international trade, was forced to leave by Economy Minister Raquel Buenrostro after four years on the job, according to the people, who requested anonymity because they don’t have permission to speak publicly. Several other top personnel from the economy ministry were asked to resign alongside De la Mora, as part of changes in the ministry’s leadership, the people said.

De la Mora wasn’t immediately reachable by phone or text. The Economy Ministry didn’t immediately reply to a request for comment.

Mexico is in difficult negotiations with its major trading partners, the US and Canada, because of their allegations that the energy policies of Lopez Obrador discriminate against foreign firms. The president has sought to reinforce the power of Petroleos Mexicanos, the state oil company, and the Comision Federal de Electricidad, rolling back some of the privatization pushed by prior governments. 

Buenrostro’s arrival had already been interpreted by analysts as a signal that Lopez Obrador was hardening his stance. The trading partners have so far remained in the consultation phase of the trade talks, avoiding the need for an arbitration panel. Yet recent developments make such an outcome more likely, according to Janneth Quiroz Zamora, vice president of economic research at Monex Casa de Bolsa.

“The change that happened today and the change of minister are two signs that point toward an increased probability that Mexico will end up paying a fine,” Zamora said in an interview. “If Mexico defends its position in implementing its policies and doesn’t reach an agreement, it’ll have to pay.”