Carlos Barria / Reuters Secretary of State Rex Tillerson said last month that people are smiling in the halls of his department.

The senior official charged with remaking the State Department in Secretary Rex Tillerson’s image has resigned after three months on the job, an agency spokesman confirmed to NBC on Monday.

Maliz Beams, who was touted on the State Department website as having led “highly successful organizational transformations” at various financial firms, stepped down as a counselor to the department and said she would return to Boston, according to the spokesman’s statement. Tillerson’s deputy chief of staff, Christine Ciccone, will “step in to lead the Redesign effort.”

“We appreciate Maliz sharing her expertise with us over the past few months,” the spokesman said. “We wish her the best of luck in her next venture.”

Tillerson has launched a dramatic campaign to reorganize the State Department since taking office earlier this year, including the hiring of two consulting firms to help spearhead the changes. He has called the effort “the most important thing” he can do as secretary and has pledged to slash the department’s budget and push out thousands of career diplomats.

“If I accomplish that, that will go on forever, and you will create the State Department of the future,” Tillerson said of the reorganization during a September speech at the U.S. Embassy in London.

Such plans have been met with alarm within the agency and abroad. The New York Times reported last week that more than a dozen of the State Department’s top-tier officials ― the equivalent of three- and four-star generals ― have left or been removed under Tillerson. Applications to join the Foreign Service are on track to fall 50 percent this year, and morale is low by the department’s own admission.

Earlier this month, Democrats on the House Foreign Affairs Committee wrote to Tillerson to say they were “deeply concerned by the exodus of more than 100” senior officials since January.

“The amount of talent leaving the State Department endangers the institution and undermines American leadership, security and interests around the world,” they wrote. “We remain profoundly concerned over what appears to be the intentional hollowing-out of our senior diplomatic ranks.”

Republican lawmakers ― including Sens. Bob Corker (Tenn.), chairman of the Foreign Relations Committee, and John McCain (Ariz.), chairman of the Armed Services Committee ― have said those concerns are “bipartisan in nature.”

Tillerson, for his part, has denied that spirits at the department are low.

“I walk the halls, people smile,” he told Bloomberg in October. “If it’s as bad as it seems to be described, I’m not seeing it, I’m not getting it.”