US President Barack Obama has signed a historic law repealing a ban on gays serving openly in the military.
Mr Obama completed the most sweeping social change in the military in decades after a long campaign by activists.
Critics had claimed that the new equality law would harm national security and endanger the lives of troops serving abroad.
Overturning the 'Don't Ask, Don't Tell' compromise that allowed gays to serve if they kept their sexuality secret, was a cherished goal of liberals but conservatives fought a tough campaign to keep it in place.
'We are not a nation that says 'Don't Ask, Don't Tell.' We are a nation that says, 'Out of many, we are one,'' Mr Obama said in a ceremony at the Interior Department in Washington.
'We are a nation that welcomes the service of every patriot,' Mr Obama said.
Gay and lesbian rights activists have compared the repeal of 'Don't Ask, Don't Tell' to the fall of the Berlin Wall and the racial integration of the military in 1948.
Opponents said the repeal will badly harm unit cohesion at a time when US forces are involved in Iraq and Afghanistan.
But Mr Obama argued the new law would 'strengthen our national security and uphold the ideals that our fighting men and women risk their lives to defend,' adding he was certain the military would implement the law with dedication.
'No longer will tens of thousands of Americans in uniform be asked to live a lie, or look over their shoulder in order to serve the country that they love.'
