Gay rights groups are calling for the resignation of the US Marines' top general after he asserted to reporters Tuesday that repealing "don't ask, don't tell" would cost the lives of soldiers.

General James Amos, commandant of the Marine Corps, cited a Pentagon study saying Marines fighting in Afghanistan were worried that permitting gays to serve openly could disrupt "unit cohesion."

"When your life hangs on a line, on the intuitive behavior of the young man ... who sits to your right and your left, you don't want anything distracting you," Amos told reporters at the Pentagon.

"I don't want to lose any Marines to distraction. I don't want to have any Marines that I'm visiting at Bethesda (hospital) with no legs," he said.

He added that "mistakes and inattention or distractions cost Marines' lives. That's the currency of this fight."

Amos cited the Pentagon's report on "don't ask," released earlier this month, as showing that Marines in general are more opposed to repealing the gay ban than service members in other branches of the military.

While Amos has previously publicly opposed repealing the military's 17-year-old ban on gays serving openly, this is the first time that a senior Pentagon official has suggested that the repeal would cost lives, reports the Washington Post.

Much of the Pentagon's leadership -- including Defense Secretary Robert Gates and Chairman of the Joint Chiefs of Staff Adm. Mike Mullen -- has voiced support for repealing "don't ask."

“General Amos needs to fall in line and salute or resign now," Aubrey Sarvis of the Servicemembers Legal Defense Network said in a statement. "General Amos needs to stop lobbying against his Commander-in-Chief, the Secretary of Defense, and the Chairman of the Joint Chiefs. If he cannot do that, the President should ask for his resignation."

Amos' comments came as President Barack Obama's Democratic allies in the House of Representatives pressed ahead Tuesday with a stand-alone bill that would repeal the US military ban on gays serving openly.

The House earlier this year easily passed an annual military spending bill with a provision ending "Don't Ask, Don't Tell," but the measure stalled in the Senate, where supporters of the repeal have also introduced a separate measure.

Democratic House Majority Leader Steny Hoyer said he would bring the stand-lone to a vote "soon" and urged the Senate to "swiftly take action as well so that the bill can be signed into law as soon as possible."

-- With reports from AFP