US Defense Secretary James Mattis is reportedly "appalled" by President Donald Trump's plan to ban transgender people from serving in the military.
Mattis was caught off-guard making these remarks about Trump's announcement, the New York Times reported on Friday.
The Pentagon chief was vacationing when Trump announced the policy about transgender Americans in a Twitter message, the paper reported.
Sources close to Mattis told the newspaper that the defense secretary was infuriated by the announcement, and saw it as an insult to transgender US citizens currently serving in the military.
On Wednesday morning, Trump said on Twitter that he made the decision after discussing the matter with his “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 US military,” he added.
"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,” he continued. “Thank you."
However, the military said the policy would not be changed until the White House issued further "guidance," in this regard, said a letter from Joint Chiefs of Staff Chairman Gen. Joseph Dunford.
“There will be no modifications to the current policy until the president’s direction has been received by the secretary of defense and the secretary has issued implementation guidance,” he wrote.
Mattis had been silently lobbying Republican lawmakers for months to defeat a amendment to the 2017 spending legislation that would bar the military from spending money on transition surgery or hormone therapy for transgender troops, the Times reported.
Mattis initially resisted the policy allowing transgender Americans to serve in the military, but then accepted that the policy was to remain in place, the report said.
According to a 2016 study, there are some 2,000 to 11,000 active duty service members who have identified themselves as transgender. Most of them could be affected by Trump's new policy.