The 51-year-old former rugby league star has been a part of Gatland's Wales coaching staff for the past decade and has helped the side win three Six Nations titles.
Englishman Edwards' current deal with the nation expires after next year's World Cup and that has resulted in speculation that he could move on before that time should an attractive job be offered to him.
The former Wasps coach has already stated that a head coach's role in either rugby union or rugby league could tempt him, while there is a possibility that England coach Eddie Jones could offer him a position given that his current defence coach Paul Gustard has now agreed to join Premiership club Harlequins.
Gatland understands that Edwards must do what is best for his own future, but he is keeping his fingers crossed that he will be in his coaching team in Japan.
"He's committed to us until the World Cup," Gatland told reporters. "But if other opportunities come along, he needs to consider those because he's out of contract after the World Cup.
"There are two or three world-class defensive coaches out there and he's definitely one of them."