ATLANTA (AP) — Georgia’s secretary of state Wednesday announced an audit of presidential election results he said would be done with a full hand tally of ballots because the margin is so tight.

State law requires an audit but leaves it up to the top elections official to choose the race. Secretary of State Brad Raffensperger said at a news conference that the presidential race makes the most sense. Raffensperger’s office has said there’s no evidence of systemic problems with the voting or the count that shows Democrat Joe Biden with a lead of about 14,000 votes over President Donald Trump.

Raffensperger said his office wants the process to begin by the end of the week and he expects it to take until Nov. 20, which is the state certification deadline.

“It will be a heavy lift, but we will work with the counties to get this done in time for our state certification,” Raffensperger said, flanked by local election officials on the steps of the state Capitol. “We have all worked hard to bring fair and accurate counts to assure that the will of the voters is reflected in the final count and that every voter will have confidence in the outcome, whether their candidate won or lost.”

Georgians cast nearly 5 million votes in the presidential race and counties have until Friday to certify their results.

Georgia’s two U.S. senators, Kelly Loeffler and David Perdue, earlier this week called on fellow Republican Raffensperger to resign over unspecified claims of election mismanagement. Both face close runoff elections in January that will determine which party controls the Senate. Raffensperger said he wouldn’t step down and assured the public there had been no widespread problems.