Laying the groundwork for a repeal of the policy will take more than a year, Gates said. In the interim, however, the Defense Department will start enforcing the policy "in a fairer manner," he told members of the Senate Armed Services Committee.
President Obama called for a repeal of the policy during last week's State of the Union address.
Joint Chiefs of Staff Chairman Adm. Mike Mullen also endorsed a repeal Tuesday, telling the committee it is his "personal belief" that "allowing gays and lesbians to serve openly [in the military] would be the right thing to do."
"For me, personally, it comes down to integrity," he said.