WASHINGTON – Roberta S. Jacobson, the former ambassador to Mexico who elected President Biden as his “border tsar” on the National Security Council, will resign later this month, she said on Friday, even if the government is struggling to confront a flood of migrants on the nation’s southwest border.

Ms. Jacobson, described as one of the key players in the Biden administration’s dealings with the governments in the Northern Triangle area of ​​Central America, praised Mr. Biden’s efforts to repair and reshape the nation’s immigration system after four years by President Donald J. Trump.

“You are continuing towards the architecture that the president designed: an immigration system that is humane, orderly and safe,” she said in a brief interview. “I go optimistically. The political direction is so clearly right for our country. “

Ms. Jacobson said her appointment as special assistant to the president and border coordinator in the White House should only last about 100 days – a deadline that expires in late April if she is about to leave government.

The timing of their departure is remarkable, however, and is in the midst of government efforts to reduce immigration from Honduras, Guatemala and El Salvador. Ms. Jacobson had been accused of leading these efforts when her appointment was announced that year.

Republican critics say Mr Biden’s decision to quickly reverse many of the toughest Trump-era immigration policies in his early days in office sparked a new wave of migrants from Central America, including families and children traveling alone to the border.

Biden government officials, including Ms. Jacobson, have argued that the increasing migration flow needs to be addressed at its source: especially in Central American countries where violence, war, poverty, gangs and natural disasters are forcing people to move out of their homes flee to the United States for refuge.

However, her role as one of the government’s top border officials was eclipsed late last month when Mr Biden announced that Vice President Kamala Harris would lead the government’s diplomatic efforts with the region.

In the interview, Ms. Jacobson said the President’s move to hire Ms. Harris for efforts to curb migration from Central America was not a factor in her decision to leave the country or her timing.

“I briefed and worked in support of the Vice President’s leadership on this matter,” said Ms. Jacobson. “Nobody could be happy if the Vice President took on this role. It had nothing to do with my decision. “

Two weeks ago, in a separate interview with the New York Times, Ms. Jacobson spoke at length about her plans to travel to Central America, where she expected to work with government officials to reduce the flow of migrants north towards the United States.

Last month she traveled to Mexico to discuss ways to combat illegal immigration and strengthen protection capacities for migrants with executives. Ms. Jacobson said in the interview that the trip was also an attempt to find ways to work with Central American countries, as well as possibly Canada, to ease pressure on the border with the United States.

“I would say that we – we have the beginnings of these conversations,” she said. “But right now we’re more focused on how we can work with Mexico and the Northern Triangle countries.”

In early March, Ms. Jacobson answered questions from reporters at the White House in an attempt to discourage migrants from traveling to the United States. She repeated the government’s message that the border with Mexico had remained closed.

But when she tried to translate this blunt message into Spanish, she accidentally reversed its meaning and said, “La frontera no esta cerrada” which means “the border is not closed” in English. Later in the meeting, she corrected herself and translated the message correctly.

Mr Biden’s decision to hold Mrs Harris responsible for Central American diplomacy was then viewed by the White House as an attempt to send a message that the government is taking the border issue seriously.

It also served as the first substantive guideline for the Vice President, who has stood by Mr. Biden’s side since taking office but has not overseen any specific part of the Biden agenda.

Jake Sullivan, the president’s national security adviser, said in a statement that “there is no better person to initiate a safer and more equitable approach to our southern border” than Ms. Jacobson.

He said she was leaving the government “after it shaped our relationship with Mexico as an equal partner, launched our renewed efforts with the nations of the Northern Triangle of El Salvador, Guatemala and Honduras, and underscored the government’s commitment to revitalizing the US immigration system.” . ”

Ms. Jacobson said she remains confident that the government will continue to make progress to convince the leaders of Mexico and Central American countries to work with the United States to slow the pace of migration.

“They know it’s something that can’t happen overnight,” she said of her colleagues in the Biden administration. But she added that officials in the other countries are also motivated to find solutions.

“Diplomacy is a conversation,” she said. “It’s not a monologue.”