The president's policy is discriminatory and "soaked in animus," a Washington DC district judge has ruled

A US federal judge has blocked the enforcement of President Donald Trump's executive order barring transgender people from serving in the country's military.

Issued by Trump a week after taking office in January, the order prohibited trans people from enlisting and required the Defense Department to identify and dismiss all service members, who have "a current diagnosis or history of, or exhibit symptoms consistent with, gender dysphoria."

US District Judge Ana Reyes of Washington, D.C. ruled on Tuesday that the ban is "soaked in animus" and violates the equal protection clause due to discriminating based on transgender status and sex.

"Its language is unabashedly demeaning, its policy stigmatizes transgender persons as inherently unfit, and its conclusions bear no relation to fact," she wrote in her decision.

Reyes, appointed by former US President Joe Biden, has delayed the effect of her preliminary injunction until Friday so that the Justice Department could challenge it at the US Court of Appeals for the District of Columbia Circuit.

The government "could have crafted a policy that balances the Nation's need for a prepared military and Americans' right to equal protection," and "they still can. The Military Ban, however, is not that policy. The Court therefore must act to uphold the equal protection rights that the military defends every day," she said.

A spokesperson for the Justice Department described Reyes' ruling as "the latest example of an activist judge attempting to seize power at the expense of the American people who overwhelmingly voted to elect President Trump."

"The Department of Justice has vigorously defended President Trump's executive actions, including the Defending Women Executive Order, and will continue to do so," the spokesperson stressed.

The lawsuit seeking to block Trump's executive order had been filed by a group of active-duty transgender service members and six transgender people in the process of enlisting, who have claimed that the policy is "unconstitutional."

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A senior US defense official told AP last month that about 4,200 US troops currently serving in the Army, National Guard and reserves have been diagnosed with gender dysphoria.