Crowds of people protest U.S. President Donald Trump's announcement that he plans to reinstate a ban on transgender individuals from serving in any capacity in the U.S. military, in Times Square, New York, the U.S., July 26, 2017. (Xinhua/REUTERS)

WASHINGTON, July 26 (Xinhua) -- U.S. President Donald Trump announced Wednesday that he would not allow transgender individuals to serve in the U.S. military in any capacity.

"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 tweeted.

The U.S. 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.

A ban on transgender people serving openly in the military ended last year, but a year-long review was put in place to allow the Pentagon to figure out how to bring in new transgender recruits into the military.

Trump's announcement came after U.S. Defense Secretary Jim Mattis said he was delaying the implementation of the new plan on the eve of the one-year deadline for the military to upgrade medical standards for transgender service members.

Mattis said late in June that the Pentagon needs more time to assess whether the new policy would affect the ability of the U.S. military to defend the country.

A Pentagon-commissioned study in 2016 showed that there are an estimated 1,320 to 6,630 transgender service members in the U.S. military.

It concluded that allowing them to serve openly would have a minimal impact on the readiness and health care costs of the 1.3-million-member U.S. military force.

Several Republican Congressmen have urged the Trump administration to reverse the policy on the basis that it is not in the interest of the national defense.