The U.S. diplomat in charge of refugee issues plans to leave his post within days, becoming the third senior U.S. official to depart or be re-assigned from refugee work in recent weeks.

Simon Henshaw, the acting assistant secretary of the State Department's Bureau of Population, Refugees and Migration, told colleagues in the refugee sector in an email seen by Reuters that he will be leaving the bureau at the end of next week.

In an interview on Saturday evening, Henshaw told Reuters he was leaving his position in a routine professional move unrelated to the Trump administration's policies, which have curtailed refugee admissions. A State Department spokeswoman also said Henshaw's move was routine.