U.S. President Joe Biden's son Hunter said he did not consider his decision to join the board of Ukrainian gas producer Burisma, which later sparked a scandal, a mistake.

"No, I don't think I made a mistake by taking a seat on the board," he said. He said, however, that he underestimated "how it would be used against him" and could not have foreseen the scandal that followed.

"But I can tell you that no investigation, no serious journalist has ever accused me, no one has ever concluded that I did anything wrong or that my father did anything wrong," Biden said.