Seagulls manager Hughton seemed angered his counterpart was congratulating his Liverpool players at the full-time whistle rather than shaking hands at the Amex Stadium.
Words were exchanged but Klopp is adamant there was no intent to upset Hughton and says he feels there is no problem between the managers going forward.
“It was a misunderstanding, nothing else,” he told reporters.
“I have to apologise, not for doing something wrong on purpose.
“I wanted to shake Chris’ hand and Mo Salah came across, I gave him a hug, and Chris wasn’t too happy.
“It was not on purpose and after the game I wanted to see him and I hope everything is fine.”
Watford boss Javi Gracia does not think Abdoulaye Doucoure's form will be affected by his omission from France's latest squad.