Serena Williams: 'I don't understand coach's claims'

Watch: Serena Williams calls umpire 'liar' and 'thief'Serena Williams says she wants to move on from her controversial US Open final defeat by Naomi Osaka.

In the final, the American was given a code violation for coaching, incurred a point penalty for racquet smashing and was docked a game for verbal abuse.

Williams denies she was being coached from the stands, despite her coach Patrick Mouratoglou saying he was sending her signals.

"I just don't understand what he was talking about," Williams said.

Williams, who was aiming to equal Margaret Court's record of 24 Grand Slam singles titles, said she had not received any tactics from Mouratoglou, telling the umpire she would "never cheat to win…