Warren Gatland believes Wales can mount a strong challenge to win the Rugby World Cup after its Six Nations Grand Slam triumph.

Gatland masterminded a clean sweep in his final Six Nations as coach, a comfortable victory over Ireland sealing the title.

The New Zealander will end his long reign after the World Cup and he sees no reason why he cannot sign off in style in Japan.

"I know that these guys won't go down in any match without a fight. We've got a very special group of players at the moment," Gatland said. "We enjoy each other's company, we challenge each other on a lot of things, but once we make a decision we back each other 100 per cent.

"I promise you that these guys will give 100 per cent in every game at the World Cup.

"You need a little bit of luck and hopefully we don't pick up too many injuries.

"We'll have a few months of preparation and as we have in the last few World Cups, we'll be one of the fittest teams, if not the fittest team there.

"There's some real depth, some real competition in this squad and that makes it tough on us as coaches. There are quality players that will miss out on the 31-man squad and that will be incredibly tough.

"I assure you that we'll go there with some confidence and belief that we can have a great World Cup."