Richard Grenell, an openly gay foreign policy spokesman for the Romney campaign, resigned from his recently-appointed post on Tuesday, ABC News has confirmed.

"We are disappointed that Ric decided to resign from the campaign for his own personal reasons. We wanted him to stay because he had superior qualifications for the position he was hired to fill," Matt Rhoades, the Romney campaign manager, told ABC News.

Grenell's resignation was first reported by the Washington Post's Jennifer Rubin.

"I have decided to resign from the Romney campaign as the Foreign Policy and National Security Spokesman," Grenell said in a statement obtained by the Washington Post. "While I welcomed the challenge to confront President Obama's foreign policy failures and weak leadership on the world stage, my ability to speak clearly and forcefully on the issues has been greatly diminished by the hyper-partisan discussion of personal issues that sometimes comes from a presidential campaign. I want to thank Governor Romney for his belief in me and my abilities and his clear message to me that being openly gay was a non-issue for him and his team."

Rubin reported that Grenell, who is openly gay, made his decision "after being kept under wraps" at a time when national security issues had risen to the forefront of the campaign and after activists on the right raised questions about his sexual orientation.

But, in an interview with ABC News, a source familiar with Grenell's departure from the Romney campaign disputed the "under wraps" suggestion.

This source said Grenell, whose hiring was first reported on April 19, had not yet started his duties as the campaign's top national security spokesman and was in the process of moving from Los Angeles to Boston.

Tuesday would have been his first actual day on the job.

"He wasn't under wraps; he wasn't a spokesperson yet," according to the individual with knowledge of Grenell's hiring and resignation. "If he had wanted to, he would be a spokesman right now."

Among those who called Grenell in recent days to try to persuade him not to quit: his former boss and former U.S. Ambassador to the United Nations, John Bolton; and former Republican National Committee Chairman Ken Mehlman.

The Romney campaign hired Grenell, who served as communications director at the United Nations under President Bush and worked as a spokesman for a number of prominent Republicans including George Pataki and Dave Camp, in mid April.

Shortly after the news of his hiring broke, Grenell was criticized not for his sexual orientation but for critical remarks he'd made on Twitter about Newt Gingrich and his wife Callista, Democratic women and the media. He later scrubbed the posts from his Twitter account.

But some social conservatives took issue with the Romney campaign's hiring of an openly homosexual man.

In late April, a radio host for the American Family Association said that the hiring indicated the Romney campaign's willingness to tell the so-called pro-family community to "drop dead."

"The homosexual agenda represents the single-greatest threat to religious liberty and freedom of association in America today," Bryan Fischer, the director of issue analysis at the American Family Association, said in an interview with CNN last month.

Democrats, including a member of the Obama campaign team, immediately pounced on the incident as an example of the Romney campaign caving to anti-gay forces on the right.

"Today we learned that in the year 2012, a Republican nominee for President can't have a gay person as spokesman," the Obama campaign's digital director, Teddy Goff, tweeted.

And Bill Burton, a former White House spokesman who is now the head of a Democratic super PAC, Priorities USA Action, said in an interview with ABC News that Grenell's departure was a "show of incredible weakness on the part of Mitt Romney."

Burton pronounced it a sign that Romney would be and the "beck and call" of whichever individuals or groups he needs to win in November.

ABC's Emily Friedman and Matt Negrin contributed to this report.