A Virginia GOP official who posted a message on his Facebook page that questioned whether Muslim Americans have made positive contributions to U.S. society has resigned.

Bob FitzSimmonds, treasurer of the state Republican Party, distributed his resignation letter to party officials Wednesday night.

“It seems that no matter how careful I might be, I will periodically give occasion for others to portray the party in a bad light, so long as I am a party official. After discussion with several party leaders it seems clear that I will either need to stop posting on social media or step down from my party office,” he wrote in a one-page letter to members of the party’s State Central Committee.

FitzSimmonds was unapologetic for his comments. In the letter, he said his resignation will not take effect until his position has been filled, which he said will probably happen after a state GOP meeting Aug. 16.

Last week, FitzSimmonds posted a comment about a message from President Obama marking the end of Ramadan. Obama praised Muslims for helping to build “the very fabric of our nation and strengthening the core of our democracy.”

Virgina Republican Party Treasurer Robert S. FitzSimmonds. (Courtesy photo)

“Exactly what part of our nation’s fabric was woven by Muslims?” FitzSimmonds wrote. “What about Sikhs, Animists, and Jainists? Should we be thanking them too?”

Pat Mullins and Michael E. Thomas, the chairman and vice chairman of the state GOP, later called on FitzSimmonds to resign.

Last Thursday, two top-ranking party officials told The Washington Post that FitzSimmonds had offered Mullins his resignation. But FitzSimmonds, who has not responded to repeated requests from The Post for comment, denied to a conservative blogger and on his own Facebook page that he had made such an offer.

Earlier this year, FitzSimmonds responded angrily on Facebook to a commenter who predicted that women would turn out in large numbers to vote for Barbara Comstock, a Republican running for the U.S. House seat held by Frank R. Wolf (R), who is retiring. FitzSimmonds responded using an offensive slang term.

He later apologized and deleted the remark, but Mullins and other senior Republicans called for his resignation.