Shell Smith has recently written tweets that appeared critical of Donald Trump.

Following the president’s abrupt firing of FBI Director James Comey, Shell Smith wrote that it can be hard to explain U.S. events to foreign listeners.

Just hours after Trump struck out at London Mayor Sadiq Khan following a deadly terror attack on the city, Shell Smith retweeted a message from Los Angeles Mayor Eric Garcetti praising Khan.

Trump last week appeared to back the anti-Qatar coalition — and even take partial credit for isolating Doha — but Shell Smith defended Qatari efforts to rein in terror financing following the diplomatic breakdown. She also retweeted official State Department messages calling for a de-escalation of tensions.

Saudi Arabia, the United Arab Emirates, Egypt and other nations cut ties and severed transportation links with Qatar last week, accusing the nation of supporting terrorism and allowing financing for extremist groups to flourish within its borders.

Shell Smith’s departure adds to a long list of vacancies at the State Department, which has raised concerns about the country’s ability to manage overseas crises.