WASHINGTON — Frustration boiled over Wednesday among supporters of the United States’ lead aid agency at a Washington rally, and anxious aid workers abroad scrambled to pack up households after the Trump administration abruptly pulled almost all agency staffers off the job and out of the field.

The order issued Tuesday followed 2 1/2 weeks that have seen the Trump administration and teams led by billionaire ally Elon Musk dismantle much of the U.S. Agency for International Development, shutting down a six-decade mission intended to shore up U.S. security by educating children, fighting epidemics and advancing other development abroad.

Secretary of State Marco Rubio, who has been touring Central America on his first visit in office, defended the actions while saying, “Our preference would have been to do this in a more orderly fashion.”

As it was, Rubio said, the administration would now “work from the bottom up” to determine which U.S. aid and development missions abroad were in the national interest and would be allowed to resume. “This is not about ending foreign aid. It is about structuring it in a way that furthers the national interest of the United States,” he said in the Guatemalan capital of Guatemala City.

In Washington, Democratic lawmakers and hundreds of others rallied outside the Capitol to protest the fast-moving shutdown of an independent government agency. “This is illegal and this is a coup,” California Democratic Rep. Sara Jacobs cried.

“We are witnessing in real time the most corrupt bargain in American history,” Maryland Sen. Chris Van Hollen shouted to supporters at the rally, referring to Musk, his support for President Donald Trump and his role in challenging USAID and other targeted agencies.

“Lock him up!” members of the crowd chanted. Addressing Democratic lawmakers, who have promised court battles and other efforts but have been unable to slow the assault on USAID, they said: “Do your job!”

Scott Paul, a director at the Oxfam American humanitarian nonprofit, said the damage already done meant that key parts of the global aid and development system would have to be rebuilt “from scratch.”

Jennifer Kates, senior vice president and director of the global health and HIV policy program at KFF, cited one large organization alone that expects to close up to 1,226 maternal and child-care clinics serving more than 630,000 women.

“The health care system is not one that you just press on and off … It includes people that deliver services and clinics that poor people go to,” Kates said. If the U.S. shutdown lays off staffers and closes those clinics, “you can’t just say, ‘All right, we’re ready to start again. Let’s go.'”