Members of the outgoing administration of President Trump have sent a letter to Mexican counterparts, including Energy Minister Rocío Nahle, admonishing regulatory changes they said are damaging Mexico’s investment climate.


The letter, signed last week by U.S. Secretary of State Michael Pompeo, Energy Secretary Dan Brouillette and Commerce Secretary Wilbur Ross indicated that recent government directives to regulators that favor state-owned companies create “significant uncertainty” in Mexico’s energy sector.

“In addition to harming several U.S.-backed private sector projects across the energy sector, these measures could adversely affect hundreds of millions of dollars of U.S. government public energy investments in Mexico made through the U.S. International...