US President Barack Obama promised to end the ban on gays and lesbians serving openly in the military last night.

In his State of the Union speech, he said: “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.

“It’s the right thing to do.”

He promised to repeal the 1993 law in his 2008 election campaign but was criticised by gay groups for being slow to act.

Observers said he could have signed an executive order to overturn the ban, but Obama is thought to seeking a permanent solution to the problem.

Rea Carey, executive director of the National Gay and Lesbian Task Force, expressed disappointment that Obama had not spoken of “concrete steps” to overturn the ban.

She added that the president must act to prevent further discharges while the law is still active.

Carey said: “While we know the State of the Union speech aims to present broad visions, the next time President Obama speaks to or about our community, he must provide a concrete blueprint for his leadership and action moving forward — this includes his willingness to stop the discharges happening on his watch until Congress can fulfill its responsibility to overturn the law.

“The time for broad statements is over. The time to get down to business is overdue. We wish we had heard him speak of concrete steps tonight.”

The Senate Armed Services Committee is expected to begin holding hearings on repealing the law in the coming weeks.

Chairman Senator Carl Levin told reporters earlier this week that they would include military leaders and outside witnesses.

The ban, also known as Don’t Ask, Don’t Tell, was implemented by President Bill Clinton as a compromise on allowing gays and lesbians to join the military.

In recent years, allowing gays and lesbians to serve openly has gathered more public support.

But Republicans have pledged to oppose the change, at least until the current wars in Iraq and Afghanistan are smaller or over. They also argue lifting the ban would harm recruitment and military cohesion.

The law means servicemembers cannot reveal their sexual orientation and senior officers cannot ask them about it. An estimated 13,000 troops have been fired under the law, due to outing themselves or being outed by others.