Completing the Grand Slam would mark a stunning turnaround for Wales after a "mental year" but they will have to take their game up another level to secure victory over France in the Six Nations on Saturday, said centre George North.

Wales won one match to finish fifth in last year's Six Nations and were beaten by England, Ireland, Scotland and France in the autumn to top off a forgettable year.

However, they have been transformed in 2021, winning all four of their matches in this year's Six Nations, including a 48-7 win over Italy in Rome on Saturday.

North, who is looking to seal his third Grand Slam after successes in 2012 and 2019, said there was so much on the line against the French.

"It would be a decent one to add on to the story of 2021 after last year. It's been a mental year for everyone involved from the autumn series to what we're playing for on Saturday," North told reporters.

"We know we have to be ready and how potent France are. To go to that next level we need to be at we've got to really up our game."

North, who became the youngest player to reach 100 test caps for Wales during the campaign, said the team had flown under the radar because of their woeful 2020.

"After the autumn series there wasn't much hype about us, which is always good because we like to be underdogs," North said. "The hard work the boys put in over the autumn and the early part of the Six Nations is really coming true now.

"We're far from the finished article as it is now but we've still got to take some positives out of this performance against Italy and fully focus on next week."