Chuck Hagel, who is in the running to become the next US defence secretary, previously suggested an ambassador could be unfit to serve due to his sexuality by describing him as “aggressively gay”.

“Ambassadorial posts are sensitive,” Hagel told the Omaha World-Herald in 1998, opposing the nomination of James Hormel. “They are representing America,” he said. “They are representing our lifestyle, our values, our standards. And I think it is an inhibiting factor to be gay — openly aggressively gay like Mr Hormel — to do an effective job.”

Buzzfeed.com also says Hagel, a Republican former Nebraska senator, supported the enforcement of Don’t Ask, Don’t Tell, a law which banned gay and lesbian men and women from being open about their sexuality in the US military.

In 1999, Hagel told the New York Times, ”The US armed forces aren’t some social experiment.”

Don’t Ask, Don’t Tell was finally repealed in September 2011.

President Obama’s current US Defence Secretary Leon Panetta, who retires in January, has been an advocate of LGBT equality in America’s armed forces and strongly supported the repeal of Don’t Ask, Don’t Tell.

In May, Panetta confirmed its repeal had not affected military morale or readiness.

The president of the LGBT Human Rights Campaign told the Times on Thursday that “[for Hagel] to be an appropriate candidate for any administration post, he must repudiate his comments about Ambassador Hormel.”