London - Captain Joe Root said England's year could still be judged a success even if they fail to level the Ashes series against Australia by winning the final Test at the Oval.

The home side go into Thursday's fifth and final match 2-1 down, meaning they cannot place the urn in their trophy cabinet alongside the one-day World Cup, which they won for the first time in July.

But the skipper said his players were still focused on denying Australia their first series win in England since 2001 in the game starting on Thursday.

"It's bitterly disappointing to not have got the Ashes back, but we haven't lost anything yet," he said.

"We've got to make sure that we square the series up and there's Test Championship points to play for as well which down the line could make a huge difference."

Root was adamant that despite the disappointment of failing to win the series, England could still be proud of their achievements over the summer.

"To win the first 50-over World Cup is a huge achievement for English cricket, so, absolutely, it should be seen as a successful year, but we've got a chance to level this series and make it slightly better than it looks right now so that's the full focus of the group."

England's failure has led to questions over Root's position as captain, particularly given his inconsistent batting throughout the series.

But he said he knew the direction in which he wanted to take the team and was already looking forward to trying to win the Ashes in Australia in 2021/22.

"In terms of personnel, things might change, as they have done for a while," he said.

"But ultimately we need to focus on the core group of players that are going to lead this team forward both home and away and build from that and towards winning in Australia."

The Yorkshireman was phlegmatic about the effect of captaincy on his form after a poor series by his standards, saying batting had been tough for both sides.

The standout batsman of the series has been Steve Smith, who has scored 671 runs in just five innings at an astonishing average of more than 134.

Root said England were trying to find a chink in the armour of the former Australia skipper, who is the top-ranked batsman in the world.

"We keep looking at different ways for sure, trying different things," he said.

"He's played extremely well. He's not really given many chances and we feel on a number of occasions in the first 20 balls we've beaten the bat a lot and it could have been very different but he's managed to ride that out well and when he's got in he's made it really count."

And Root paid tribute to outgoing coach Trevor Bayliss, who is returning to Australia after four years at the helm.

"He's been a part of some very special wins in Test match cricket, series home and away which he should be extremely proud of as a coach and the way he's transformed white-ball cricket and been a part of that journey is incredible," said Root.