(Reuters) - Transgender recruits will be able to join the U.S. military as of Jan. 1 after a federal judge on Monday denied a request by President Donald Trump’s administration to enforce his ban on transgender troops while the government appeals an order blocking it.

In a ruling, with which the Pentagon said it would comply, U.S. District Judge Colleen Kollar-Kotelly in Washington refused to lift part of her Oct. 30 order stopping the ban from taking effect until the case is resolved, saying it likely violated the U.S. Constitution’s guarantees of due process and equal protection under the law.

The White House said the Justice Department was reviewing its options.

The Pentagon said in a statement that it would follow court orders and begin processing transgender applicants on Jan. 1.

It added, however, that it and the U.S. Department of Justice “are actively pursuing relief from those court orders in order to allow an ongoing policy review scheduled to be completed before the end of March.”

The administration had argued that the Jan. 1 deadline was problematic because tens of thousands of personnel would have to be trained on the medical standards needed to process transgender applicants, and the military was not ready for that.

Kollar-Kotelly rejected the concerns, saying preparations for accepting transgender troops were under way during the administration of Trump’s predecessor, Barack Obama.

“The directive from the Secretary of Defense requiring the military to prepare to begin allowing accession of transgender individuals was issued on June 30, 2016 - nearly one and a half years ago,” the judge said.

Several transgender service members filed a lawsuit after Trump said in July he would ban transgender people from the military, citing concern over military focus and medical costs.

In an August memorandum, Trump gave the military until March 2018 to revert to a policy prohibiting openly transgender individuals from joining the military and authorizing their discharge. The memo also halted the use of government funds for sex-reassignment surgery for active-duty personnel.

Defense Secretary James Mattis had previously delayed a deadline that had been set during the Obama administration to begin enlisting transgender recruits to Jan. 1, which Trump’s ban then put off indefinitely.

PENTAGON GUIDELINES

The Pentagon said on Monday there were a number of guidelines that would have to be met by the applicants.

FILE PHOTO: U.S. President Donald Trump delivers remarks to U.S. military personnel at Naval Air Station Sigonella following the G7 Summit, in Sigonella, Sicily, Italy, May 27, 2017. REUTERS/Darrin Zammit Lupi

It said that sex reassignment or genital reconstruction would be disqualifying factors unless a medical provider certified that a period of 18 months had passed since the most recent surgery, no complications persisted and additional surgeries are not required.

The service members who sued Trump, Mattis and military leaders in August had been serving openly as transgender people in the U.S. Army, Air Force and Coast Guard. They said Trump’s ban discriminated against them based on their sex and transgender status.

In her October ruling, Kollar-Kotelly said the Trump administration’s reasons for the ban “do not appear to be supported by any facts” and cited a military-commissioned study that debunked concerns about military cohesion or healthcare costs.

A federal judge in Maryland also halted the ban in Nov. 21 ruling.