WASHINGTON - US President Donald Trump's re-election campaign is seeking an additional presidential debate in early September, according to a letter sent by Trump's personal lawyer on Wednesday to the Commission on Presidential Debates.

In the letter, Rudolph Giuliani, who is also former mayor of New York, asked the commission to "modernize its line-up to include an additional, earlier debate in September, bringing the total number of presidential debates to four."

The commission has scheduled three presidential debates on Sept 29 in Ohio, Oct 15 in Florida and Oct 22 in Tennessee.

Giuliani argued that million of Americans in 16 states will have already started voting by the time the first debate takes place.

"For a nation already deprived of a traditional campaign schedule because of the COVID-19 global pandemic, it makes no sense to also deprive so many Americans of the opportunity to see and hear the two competing visions for our country's future before millions of votes have been cast," Giuliani wrote.

The solution is to add a debate in early September before the first ballots are sent out in North Carolina on Sept 4, he wrote.

If the commission refuses an additional debate, it should move the final one into the first week in September, Giuliani added.

Andrew Bates, spokesman of former Vice President Joe Biden's campaign, said in a statement that Biden has already committed to participating in the scheduled debates, according to a Reuters report.

"Joe Biden will be there. We await Donald Trump's decision - and perhaps the president should put as much time into managing COVID as he does into this," Bates was quoted as saying by Reuters.