"My dual citizenship has become a distraction in this campaign," Oz, a U.S. citizen who was born in Ohio, said in a statement from his campaign. "I maintained it to care for my ailing mother, but after several weeks of discussions with my family, I’m committing that before I am sworn in as the next U.S. Senator for Pennsylvania I will only be a U.S. citizen."
Oz's plans were first reported by Fox News.
Dave McCormick, one of Oz's chief rivals for the GOP nomination, had made his dual citizenship an issue in the primary. Earlier Thursday, McCormick's campaign hosted a conference call with Sen. Dan Sullivan, R-Alaska, who raised concerns that Oz's Turkish citizenship would limit his access to intelligence about foreign countries.
"My view is you need full access to all the intel that the intelligence agencies provide U.S. senators to do the job effectively," Sullivan said on the call.
Oz, in his statement, called the attacks on his dual citizenship "bigoted" and a "sign of McCormick’s desperate campaign that he has resorted to this disgraceful tactic."
McCormick pressed Oz in a statement from his campaign later Thursday to renounce his Turkish citizenship immediately.
"Do it now," McCormick said. "Voters can’t trust Mehmet Oz."
Pennsylvania's Senate race is one of the most competitive in the country, and the GOP primary is particularly chaotic. Oz and McCormick, a former hedge fund executive, entered the race after Sean Parnell, who had former President Donald Trump's endorsement, dropped out when his estranged wife was granted sole legal custody of their children in a case in which she alleged abuse. Parnell denied the accusations.
A Fox News poll last week showed McCormick leading the crowded Republican field, at 24 percent among primary voters, followed by Oz, at 15 percent. Both have spent millions of dollars on TV ads.