Kimberly Breier, the top U.S. diplomat for the Western Hemisphere, is stepping down, she confirmed Thursday, leaving a critical State Department position vacant at a time of high tension in the region.
In her July 24 resignation letter obtained by NBC News, Breier said her service as assistant secretary of state for Western Hemisphere affairs had been a privilege, but she wanted to spend more time with her family.
“The WHA team has many successes to its credit, from launching a productive relationship with the new government in Mexico, to our unprecedented Venezuela policy, to taking full advantage of the new era in South America and beyond," Breier wrote, expressing satisfaction with her accomplishments during her nearly 10 months in office.
"It has been a dynamic time and I am proud that we have seized opportunities at the same time as we have tried to find new solutions to some of the region’s toughest problems.”
But two U.S. officials tell NBC News that Breier had expressed frustration with the process around the administration’s immigration policies and at being micromanaged by the White House.
She “wanted to do her own thing,” one official said, and preferred to proceed more cautiously, keeping delicate diplomatic conversations and disagreements behind closed doors rather than being aired publicly by President Donald Trump.
The rapid change in U.S. policy in the region made her “uncomfortable” and contributed to her decision to resign, the official said. Both officials said the decision had been mounting for some time.
Immigration has been the defining issue of the Trump administration’s relationship with Mexico and Central American governments, and Breier has often been on the front lines of difficult conversations. Breier led the U.S. delegation in over 12 hours of tense discussions with Mexico about stemming the flow of migration across the U.S.-Mexico border.
Her success neutralized Trump’s threat of imposing tariffs and resulted in a temporary migration agreement.
The Mexican ambassador to the U.S., Martha Bárcena Coqui, thanked Breier for her “constructive approach,” and acknowledged her “deep understanding” of Mexico.
The Washington Post first reported the resignation, citing in part an unpleasant email exchange between Breier and White House policy adviser Stephen Miller over a recent asylum agreement the U.S. signed with Guatemala, a claim the U.S. State Department denies.
“There is absolutely no truth to that,” spokeswoman Morgan Ortagus said, recounting direct conversations with Breier about the report. “She has denied ever seeing this email.”
Ortegus said Breier's resignation is effective at the end of August.
Breier's is the latest in a series of high-level departures from the agency, which is already burdened with top positions left long vacant and many more filled with temporary leadership.
The head of the State Department’s office of policy planning, Kiron Skinner, left less than a week before Breier’s announcement; the assistant secretary for arms control verification and compliance, Yleem Poblete, resigned in May; and the assistant secretary for Europe, Wess Mitchell, resigned in January.
Both top diplomatic positions for Europe and South Central Asia are filled by officials leading in an “acting” capacity.