Secretary of State Rex Tillerson (L) sits beside U.S. President Donald Trump during a cabinet meeting at the White House in Washington, U.S., November 1, 2017. REUTERS/Kevin Lamarque

WASHINGTON (Reuters) - A chorus of concern in the U.S. Congress over the potential national security threat of State Department staff cuts grew on Thursday when every Democrat on the House of Representatives Foreign Affairs Committee signed a letter asking for a briefing.

“The number of minister counselors in the State Department has decreased by 15 percent, career ministers by 42 percent, and career ambassadors by an astounding 60 percent,” they said in the letter to Secretary of State Rex Tillerson.

“The amount of talent leaving the State Department endangers the institution and undermines American leadership, security and interests around the world,” said the letter, led by Representative Eliot Engel, the top Democrat on the committee.

Many members of Congress, Democrats as well as some of President Donald Trump’s fellow Republicans, have rejected Trump’s proposal to cut the State Department budget by about 30 percent. Tillerson has embraced the plan, and imposed a hiring freeze while analyzing the agency’s operations and deciding how to reorganize them.

On Tuesday, the Republican chairman and top Democrat on the Senate Foreign Relations Committee both blasted the agency for cuts in staff and what they described as a failure to have a plan for a proposed organization.

On Wednesday, Republican Senator John McCain, the Senate Armed Services Committee chairman, and Democratic Senator Jeanne Shaheen, the top Democrat on a Foreign Relations subcommittee overseeing State, delivered a letter to Tillerson asking him to begin consulting with lawmakers on decisions that have an impact on recruiting, retaining and staffing, removing a hiring freeze and resuming promotions. [L1N1NL2AB]

Tillerson has said his reorganization plan aimed to increase efficiency and cut costs, with a target of saving at least 10 percent, or about $5 billion, over the next five years from fiscal-year 2017 levels.

A State Department spokesperson said that all congressional correspondence to the department is reviewed and receives an appropriate response. “We can affirm that the Secretary has said on many occasions that he will advocate for any resources or reforms America’s diplomats need to do their jobs,” the spokesperson said in a email.