WASHINGTON (Reuters) - The Pentagon will unveil steps next week that the military will take to lay the ground for a repeal of its "don't ask, don't tell" policy, which permits gays to serve in uniform as long they hide their sexual orientation, officials said on Thursday.

Defense Secretary Robert Gates and the chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, will present an "implementation plan" to U.S. lawmakers next Tuesday, spelling out measures that the Pentagon will take internally before the White House and the Congress move to change the law.

In his first State of the Union speech on Wednesday, President Barack Obama called for ending the policy, saying: "This year, I will work with Congress and our military to finally repeal the law that denies gay Americans the right to serve the country they love because of who they are."

Gates has voiced caution in the past against moving too quickly to repeal the Pentagon's "don't ask, don't tell" policy, which began in the early 1990s...