FILE PHOTO: U.S. Secretary of State Mike Pompeo holds a press briefing at U.N. headquarters in New York City, New York, U.S., July 20, 2018. REUTERS/Brendan McDermid/File Photo

WASHINGTON (Reuters) - Thirty-two former U.S. diplomats and 11 aid groups on Monday urged U.S. Secretary of State Mike Pompeo not to eliminate a key State Department refugee bureau, warning that the move would be “an error of grave proportion.”

In a letter to Pompeo, the former diplomats and national security advisers who served in both Democratic and Republican administrations said eliminating the Bureau of Population, Refugees and Migration (PRM) office would impact the U.S. ability to influence global refugee policy.

The letter comes barely a year after 58 U.S. policy experts warned Rex Tillerson, the former secretary of state, against such a move.

“We believe this would be an error of grave proportion, and we would urge close consultation with the U.S. Congress before such a critically important measure is even considered,” the former officials and aid groups wrote.

Since taking office in January last year, the Trump administration has cut the number of refugees it admits into the country, introduced stricter vetting rules and quit negotiations on a voluntary pact to deal with global migration.

“We are convinced that the elimination of PRM’s assistance functions would have profound and negative implications for the Secretary of State’s capacity to influence policy issues of key concern to the United States,” the groups wrote. “It would also be ironic, as this is one of the bureaus at State that has enjoyed strong bipartisan support over many years.”

The State Department did not respond to questions about the possible removal of the refugee office.

Those signing the letter included William Burns, former deputy secretary of state; Rand Beers, former deputy assistant to the president for homeland security; Nicholas Burns, former under secretary of state for political affairs; Ryan Crocker, former ambassador to Afghanistan, Iraq, Pakistan, Syria, Kuwait and Lebanon; Ellen Laipson, former vice chair of the U.S. National Intelligence Council; Anne Richard, former assistant secretary of state for PRM; and Frederick Barton, a former U.N. deputy high commissioner for refugees.

Among the aid groups that signed the letter was Scott Arbeiter, president of World Relief; David Miliband, president of International Rescue Committee; Eric Schwartz, president of Refugees International and former assistant secretary of state for population, refugees and migration; Wendy Young, president of Kids in Need of Defense; and Neal Keny-Guyer, CEO of Mercy Corps.