WASHINGTON — Roberta S. Jacobson, the former ambassador to Mexico whom President Biden chose as his “border czar” on the National Security Council, will step down at the end of the month, she said on Friday, even as the administration struggles to confront a surge of migrants at the nation’s southwestern border.
Ms. Jacobson, who had been described as one of the Biden administration’s key players in dealing with the governments in the Northern Triangle area of Central America, praised Mr. Biden’s efforts to repair and recast the nation’s immigration system after four years under President Donald J. Trump.
“They continue to drive toward the architecture that the president has laid out: an immigration system that is humane, orderly and safe,” she said in a brief interview. “I leave optimistically. The policy direction is so clearly right for our country.”
Ms. Jacobson said that her appointment as a special assistant to the president and as the border coordinator in the White House was always intended to last for only about 100 days — a period that will expire at the end of April, when she intends to leave government.
Vice President Kamala Harris would lead the government’s diplomatic efforts with that region.
In the interview, Ms. Jacobson said the president’s move to put Ms. Harris in charge of the effort to stem migration from Central America was not a factor in her decision to leave or her timing.