"Be patient. What is important is that we get it right. We get it accurate," said Jonathan Marks, Deputy Secretary for Elections and Commissions for the Pennsylvania Department of State.
Marks says there are fewer than 10,000 mail-in ballots outstanding for the Republican primary statewide. The majority of those votes are in Lancaster County where thousands of mail-in ballots were delayed because of a printing error.
"Lancaster County has completed the process for the most part. They had about 600 to 800 ballots they had to review," said Marks.
SEE ALSO: Pa. primary: Thousands of votes still being counted as Oz, McCormick locked in tight race
Pa. primary: Thousands of votes still being counted as Oz, McCormick locked in tight race
Meanwhile, former President Donald Trump, who has publicly endorsed candidate Oz, has called into question the validity of Pennsylvania's mail-in voting process, which elections officials dispute.
"Mail-in voting is safe and it's secure and the voters of Pennsylvania and certainly Philadelphia should feel secure in that vote," said Lisa Deeley, chairwoman for the Philadelphia City Commissioners.
While Philadelphia County has the most total ballots left to count, we're told only a few hundred are Republican votes.
With the margin for the Oz and McCormick race narrowing by the hour, it could come down to a recount.
Pennsylvania law requires recounts when the margin between the top two candidates is 0.5 percentage points or less.
"We're going to get updated unofficial returns next Tuesday from all 67 counties, and only at that point are we going to be able to say whether a statewide recount is necessary or not," said Marks.
If there is a recount, Marks says those results have to be in by June 7.