President Andrés Manuel López Obrador appointed Raquel Buenrostro as Mexico’s economic secretary on Friday, the day after the abrupt resignation of Tatiana Clouthier.

The resignation came amid difficult negotiations over USMCA disputes with the United States and Canada.

A top priority for Buenrostro, who headed tax authority SAT, will be to negotiate the U.S.-led dispute that Mexico is trying to prevent from turning into treaty arbitration.

The conflict stems from a set of Mexican policies that the United States and Canada say harm private businesses and unfairly favor state-owned companies. In particular, they point to changes in shipping priority rules and growing barriers to obtaining permits in the energy sector, as well as controversial gas pipeline regulations.

According to Kenneth Smith Ramos, former USMCA head of negotiations for Mexico, Clouthier’s resignation has raised concerns in the energy sector, news outlet Energía a Debate reported.

Clouthier’s departure is likely unrelated to the treaty dispute, energy consultant Rosanety Barrios told BNamericas.

The discussions between the three countries have extended beyond their initial period. Although the United States and Canada could have asked for the formation of a panel of experts after October 3, the two nations seem to prefer a negotiation.

The Mexican section of the International Chamber of Commerce said in a statement that Buenrostro is known for “listening and responding to proposals from the business world, with the aim of achieving the best productivity conditions for Mexico.”