Secretary of State Marco Rubio unveiled a plan on Tuesday to make major cuts to the State Department as part of a restructuring, calling the government’s diplomatic agency “bloated, bureaucratic” and “beholden to radical political ideology.”

Mr. Rubio released the plan in the form of an organizational chart and a brief official statement. The move is the latest by the Trump administration to reduce and reshape the government to a degree unseen in generations, which critics call a shortsightedly blunt assault on the federal bureaucracy.

The announcement on Tuesday focused mainly on changes to operations in Washington, but the cuts will affect the work of embassies and consulates overseas, and closures of diplomatic missions and layoffs abroad are expected later, according to U.S. officials and earlier leaked memos.

The most dramatic change is the elimination of the office of the under secretary for civilian security, democracy and human rights, which is charged with advancing American values around the world. Trump administration officials call the office a hotbed of liberal activism.

Some elements of that office, including a bureau for democracy and human rights and one for refugees, would be cut and folded into an office for foreign assistance and humanitarian aid, according to the reorganization chart posted on the State Department website. A counternarcotics bureau would also be cut and moved under an international security office.

The department released an internal fact sheet that provided more details on Mr. Rubio’s plan, including reducing the agency’s total number of bureaus and offices from 734 to 602, or by about 18 percent. The sheet did not specify all the offices. It also said that Mr. Rubio had instructed senior officials to deliver plans to reduce the number of U.S.-based employees by 15 percent.