A federal judge cleared the way Monday for the Defense Department to begin taking in transgender recruits Jan. 1.

Judge Colleen Kollar-Kotelly of the U.S. District Court for the District of Columbia rejected the Justice Department's motion for a delay in her October ruling that President Donald Trump's proposed ban on transgender individuals in the military was discriminatory and unconstitutional.

It was not immediately clear whether the Trump administration would appeal, but Maj. David Eastburn, a Pentagon spokesman, said the enlistment of transgender recruits will start Jan. 1 and continue until such time as the courts rule otherwise.

At the White House later, Press Secretary Sarah Huckabee Sanders indicated Trump has not given up on imposing a transgender ban for the military, saying the Justice Department is "currently reviewing legal options" to find a way to have the directive implemented.

"The Court is not persuaded that Defendants [the Trump administration] will be irreparably injured" by meeting the New Year's Day deadline, Kollar-Kotelly wrote in her ruling.

"Especially in light of the record evidence showing, with specifics, that considerable work has already been done, the Court is not convinced by the vague claims in [the administration's] declaration that a stay is needed," she said.

In October, Kollar-Kotelly granted a preliminary injunction sought by plaintiffs for advocacy groups in the case of Doe v. Trump against the president's August directive to ban transgender individuals from serving in the military.

Kollar-Kotelly's action had the effect of ordering the Defense Department to resume accepting qualified transgender individuals Jan. 1. The DoD initially said that the military was ready to comply with the court's ruling.

"While reviewing legal options with the Department of Justice, the Department of Defense is taking steps to be prepared to initiate accessions of transgender applicants for military service on January 1," Eastburn said in a statement.

However, last week, Lernes Hebert, acting deputy assistant secretary of defense for personnel policy, filed papers supporting the administration's request for a delay. He said accepting transgender recruits by Jan. 1 would "impose extraordinary burdens" on the military.

In granting the preliminary injunction in October, Kollar-Kotelly sided with plaintiffs in the case who argued that Trump's move to bar transgender recruits and to discharge transgender individuals already in the ranks was illegal.

"There is absolutely no support for the claim that the ongoing service of transgender people would have any negative effect on the military at all," Kollar-Kotelly wrote.

"In fact, there is considerable evidence that it is the discharge and banning of such individuals that would have such effects," she said.

On July 26, Trump in a series of Tweets announced his intention to ban transgender individuals from serving in the military.

Trump said that the government would no longer "accept or allow transgender individuals to serve in any capacity in the U.S. military." His announcement caught the DoD by surprise.

On July 27, Joint Chiefs Chairman Gen. Joseph Dunford issued a statement indicating that the military would not make changes on transgender personnel until Trump made clear his intentions.

"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," Dunford said in a memo to the service chiefs and senior enlisted advisers.

Trump followed up the Tweets with a memo to the DoD ordering a ban and directing Defense Secretary Jim Mattis to conduct a study on the effects and costs of transgenders in the ranks.

In remarks to reporters at his Bedminster, New Jersey, estate, Trump said, "As you know, it's been a very complicated issue for the military, it's been a very confusing issue for the military, and I think I'm doing the military a great favor."

A Rand Corp. study estimated there are between 2,500 and 7,000 transgender service members on active duty and an additional 1,500 to 4,000 in the Reserves and National Guard.

The case against the administration was brought by GLBTQ Legal Advocates and Defenders [GLAD] and the National Center for Lesbian Rights [NCLR].

The advocacy groups sued in August on behalf of six active-duty transgender service members who had come out to their superiors and had roughly 60 years combined in the military.

In a statement in response to Kollar-Kotelly's issuance of a preliminary injunction against the administration, NCLR legal director Shannon Minter said:

"This is a complete victory for our plaintiffs and all transgender service members, who are now once again able to serve on equal terms and without the threat of being discharged."

Last year, then-Defense Secretary Ash Carter ended the ban on transgender service members, allowing them to serve openly in the military. He said that within 12 months -- or by July 2017 -- transgender people also would be able to enlist.

-- Richard Sisk can be reached at Richard.Sisk@Miitary.com.