By Phil Stewart and Doina Chiacu
WASHINGTON (Reuters) - President Donald Trump said on Wednesday he would not permit transgender people to serve in the U.S. military, citing "tremendous medical costs and disruption," an action condemned by critics as "raw prejudice" and a political stunt.
It was not the first time Trump had targeted transgender people since taking office in January. The Republican president in February rescinded protections for transgender students put in place by his predecessor, Democrat Barack Obama, that had let them use bathrooms corresponding with their gender identity.
"After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow transgender individuals to serve in any capacity in the U.S. Military," Trump wrote in a series of Twitter posts.
"Our military must be focused on decisive and overwhelming victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail," the Republican president wrote.
Trump's action appeared to halt years of efforts to eliminate barriers to military service based on sexual orientation. The Pentagon last year under Obama announced that it was ending its ban on transgender people serving openly in the military, with officials calling the prohibition outdated.
The Defense Department on Wednesday referred all questions about Trump's decision to the White House. "We will provide revised guidance to the department in the near future," Defense Department spokesman Navy Captain Jeff Davis said.
The Pentagon had been expected to start allowing transgender people to begin enlisting this year, provided they had been "stable" in their preferred gender for 18 months. But Defense Secretary Jim Mattis on June 30 approved a six-month delay in allowing transgender recruits to join the military.
American Civil Liberties Union attorney Joshua Block called Trump's action outrageous and desperate, saying the president rejected the "basic humanity" of transgender service members.
"This has been studied extensively, and the consensus is clear: There are no cost or military readiness drawbacks associated with allowing trans people to fight for their country," Block said. "The president is trying to score cheap political points on the backs of military personnel who have put their lives on the line for their country."
The top Democrat in the House of Representatives, Nancy Pelosi, noted that a study commissioned by the Pentagon found that the cost of providing medically necessary transition-related care involving transgender service members would amount to one-100th of 1 percent of the military's healthcare budget.
"Once again, President Trump has shown his conduct is driven not by honor, decency, or national security, but by raw prejudice," Pelosi said,
The U.S. Supreme Court in March scrapped plans to hear a major transgender rights case and threw out a lower court's ruling in favor of a transgender Virginia high school student after Trump rescinded Obama's policy.
The U.S. military's ban on gays serving openly in the armed forces ended under Obama in 2011 after Congress passed legislation in 2010 reversing a law dubbed "don't ask, don't tell" that had forced the ouster of thousands of service members and others to hide their sexual orientation.
The U.S. military at times has been in the vanguard of social progress in the United States, for example Democratic President Harry Truman's racial integration of the armed forces in 1948 before the civil rights battles of the 1950s and 1960s.
The Pentagon under Obama also opened all combat roles in the military to women.
Last year, Obama's defense secretary, Ash Carter, cited a study by the RAND Corporation think tank saying there were about 2,500 transgender active-duty service members and 1,500 reserve transgender service members.
A study by the military published this year in Journal of the American Medical Association Internal Medicine showing that most of its family physicians reported in 2016 that they had not been formally trained to care for transgender individuals. At least one military medical center had implemented training for its doctors, however.
The ACLU and the gay and transgender rights group Lambda Legal appealed to transgender service members to contact their lawyers for help.
(Reporting by Lawrence Hurley, Susan Heavey and Doina Chiacu in Washington, Andrew Seaman in New York; Writing by Will Dunham; Editing by Jonathan Oatis)