The state department is firing more than 1,300 employees on Friday in line with a dramatic reorganisation plan initiated by the Trump administration earlier this year.

The department is sending layoff notices to 1,107 civil servants and 246 foreign service officers with domestic assignments in the US, said a senior state department official, who spoke on the condition of anonymity to discuss personnel matters ahead of individual notices being emailed to affected employees.

Foreign service officers affected will be placed immediately on administrative leave for 120 days, after which they will formally lose their jobs, according to an internal notice obtained by The Associated Press.

For most affected civil servants, the separation period is 60 days, it said.

“In connection with the departmental reorganisation … the department is streamlining domestic operations to focus on diplomatic priorities,” the notice says. “Headcount reductions have been carefully tailored to affect non-core functions, duplicative or redundant offices, and offices where considerable efficiencies may be found from centralisation or consolidation of functions and responsibilities.”

While lauded by President Donald Trump, secretary of state Marco Rubio and their Republican allies as overdue and necessary to make the department leaner, more nimble and more efficient, the cuts have been roundly criticised by current and former diplomats who say they will weaken US influence and its ability to counter existing and emerging threats abroad.

The Trump administration has pushed to reshape American diplomacy and worked aggressively to shrink the size of the federal government, including mass dismissals as part of moves to dismantle whole departments like the US Agency for international development and the education department.

A recent ruling by the Supreme Court cleared the way for the layoffs to start, while lawsuits challenging the legality of the cuts continue to play out. The department had formally advised staffers on Thursday that it would be sending layoff notices to some of them soon.

The job cuts are large but considerably less than many had feared.

Rubio said officials took “a very deliberate step to reorganise the state department to be more efficient and more focussed”.

“It’s not a consequence of trying to get rid of people. But if you close the bureau, you don’t need those positions,” he told reporters on Thursday in Kuala Lumpur where he’s attending the annual Association of Southeast Asian Nations Regional Forum.