Sprint legend Usain Bolt said he could have emerged from retirement to win a fourth straight Olympic 100m title in Tokyo this year, insisting the winning time was within his reach.

Bolt, 35, said that it was frustrating to watch the delayed 2020 Games from his home in Jamaica as his male countrymen flopped and Italy's Lamont Jacobs claimed a shock victory.

"I really missed it. I was like, I wish I was there," he said in an interview at the Dubai offices of his sponsor PepsiCo on Sunday.