In hosting a gay pride event Tuesday at the White House, President Barack Obama promised to push for repeal of “Don't Ask, Don't Tell.”

“We have never been closer to ending this discriminatory policy and I'm gong to keep on fighting till that bill is on my desk,” Obama told the crowd.

Late last month, the House approved a version of the Defense Authorization Bill that includes Pennsylvania Rep. Patrick Murphy's amendment that repeals the 1993 law that forbids gay troops from serving openly. The Senate is expected to take up the issue next month after the Senate Armed Services Committee voted in favor of attaching similar repeal language to their version of the defense bill.

Obama has previously promised to repeal the policy that has ended the military careers of an estimated 13,000 gay and lesbian service members.

“I will end 'Don't Ask, Don't Tell',” Obama said last October at a fundraiser for the Human Rights Campaign (HRC), the nation's largest gay rights advocate. “That is my commitment to you.”

Tuesday the president said successful repeal of the law depends on Congress having the support of Defense Secretary Robert Gates and Admiral Mike Mullen, chairman of the Joint Chiefs of Staff.

“The only way to lock this in, the only way to get votes of Congress to roll back this policy, is if we work with the Pentagon who are in the midst of two wars,” he said.

Gates and Mullen testified before a congressional committee earlier that they support repeal.

But speaking on Fox News Sunday, Gates said that Obama probably still would veto the defense spending bill if it includes defense projects labeled as wasteful.

“It would be a very serious mistake to believe that the president would not veto a bill that has the C-17 or the alternative engine in it just because it had other provisions that the president and the administration want,” Gates told Chris Wallace.

Earlier Obama declared June gay, lesbian, bisexual and transgender pride month.

But even as Obama used the event to highlight some of the gay rights initiatives advanced in his administration – passage of a federal hate crimes law that includes sexual orientation and gender identity, elimination of the HIV travel ban and an order extending hospital visiting rights to gay couples – gay activists say he's yet to deliver on meaningful issues.

Robin McGehee, co-founder of the gay rights group GetEQUAL, told that the Obama administration has failed on the gay community's most pressing issues.

The White House “has done little to end the firings of gay and lesbian service members, place pressure on Democratic leaders in Congress to pass ENDA, or advance legislation to repeal the Defense of Marriage Act.”

McGehee also criticized the administration's “deafening silence” on gay-inclusive immigration reform and passage of legislation that tackles the problem of anti-gay, anti-transgender bias in the schools.

Speaking at a gay pride celebration Tuesday, Secretary of State Hillary Clinton pledged to defend gay rights at home and abroad.