Senators John McCain, Orrin Hatch, Richard Shelby and Joni Ernst are among the Republican lawmakers voicing their opposition to a ban on transgender troops.

The lawmakers spoke out after President Donald Trump declared in a series of tweets Wednesday that the military will no longer “accept or allow” transgender troops to serve “in any capacity.”

(Related: Trump says military will bar transgender troops.)

On Thursday, the Pentagon clarified that the policy on transgender troops had yet to change.

(Related: Pentagon: No official change has been made on transgender service.)

McCain, who chairs the Senate Armed Services Committee, criticized the president in a statement posted on his Senate website.

“The Department of Defense has already decided to allow currently-serving transgender individuals to stay in the military, and many are serving honorably today,” the Arizona senator wrote. “Any American who meets current medical and readiness standards should be allowed to continue serving. There is no reason to force service members who are able to fight, train, and deploy to leave the military – regardless of their gender identity. We should all be guided by the principle that any American who wants to serve our country and is able to meet the standards should have the opportunity to do so – and should be treated as the patriots they are.”

Utah Senator Orrin Hatch said in a statement that “transgender people are people, and deserve the best we can do for them.”

Appearing on CNN's Newsroom, Shelby, a senator from Alabama, backed the current policy. “You ought to treat everybody fairly and give everybody a chance to serve. The current policy is a big tent for people who want to serve. You have to remember our military force is a volunteer force.”

A spokeswoman for Ernst, a senator from Iowa, told The Des Moines Register that Ernst believes that “Americans who are qualified and can meet the standards to serve in the military should be afforded that opportunity” provided taxpayers don't “cover the costs associated with a gender reassignment surgery.”