Richard Sauber, special counsel to the president, told House Oversight Chairman James Comer (R-Ky.) that the president would not testify in the "partisan charade."

"Your committee's purported 'impeachment inquiry' has succeeded only in turning up abundant evidence that, in fact, the president has done nothing wrong," Mr. Sauber said in a letter to Mr. Comer.

"Your insistence on peddling these false and unsupported allegations despite ample evidence to the contrary makes one thing about your investigation abundantly clear: The facts do not matter to you," he added.

Republicans in their investigation have found that millions of dollars flowed from businesses and individuals, including foreigners, to members of the Biden family while President Biden was vice president.

They've also identified payments from Hunter Biden's business to the president, and from the president's brother to him, as well as emails between President Biden and an associate of Hunter Biden. Several witnesses, meanwhile, testified that President Biden would get on the phone with Hunter Biden's associates and that he attended multiple meals with them.

President Biden and the White House have maintained that he was not involved with the business undertaken by his son and brother.

Mr. Comer wrote to the president in March, saying the evidence "wholly contradicts your position."