BREAKING: PA GOP Senate primary too close to call, may go to recount

According to Pennsylvania state law, an automatic recount is required for statewide races that are within .5 percent of the total vote.

McCormick had led for most of the night, but Oz outperformed in Bucks County, closing the gap, and now trails by only a few thousand votes. More that 1.1 million votes have already been counted.

Additionally, thousands of mailed ballots are being recalled in the Pennsylvania primary after election officials found printing mistakes that made the ballots incalculable, which could delay results further.

In Pennsylvania, at least 21,000 mailed ballots in Lancaster County, were unable to be scanned due to an error in the barcode. Officials said the company that printed the ballots included the wrong ID code, which prevented scanning machines from being able to read them.

To fix the issuse, election workers will have to hand-mark fresh ballots, which could take several days.

Kathy Barnette, who had been surging in polling after her Newsmax debate performance just over a week ago, pulled in only 24 percent of the vote behind the two leaders.

Oz and McCormick each predicted victory in their speeches to supporters Tuesday night.

McCormick said at his election night party, "We are going to win this campaign. Right now we have tens of thousands of mail-in ballots that have not be counted... unfortunately we're not going to have resolution tonight. But we can see the path ahead, we can see victory ahead."

Oz told his supporters, "So we're not going to have a result tonight. When all the votes are tallied, I am confident we will win."

The eventual winner of the GOP primary will face Democrat nominee Lt. Gov. John Fetterman, who won his race despite suffering a stroke last week and underwent surgery on election day.

Meanwhile, Pennsylvania state legislator Doug Mastriano is projected to win the Republican primary in state’s open governor's race Tuesday night. Mastriano’s victory continues Trump’s "kingmaker" winning streak in Republican primaries across the US.

This is a breaking story and will be updated.