Andy Farrell believes Ireland have "a long way to go" before reaching the peak of their powers despite winning the Grand Slam.
Ireland were crowned Six Nations champions on Saturday after beating England 29-16 at the Aviva Stadium.
Farrell's side are top of the rankings following 10 consecutive victories and will be expected to mount a strong challenge to win the Rugby World Cup for the first time in France later this year.
Yet the Ireland head coach is demanding more from his players after they celebrated a fourth Grand Slam triumph.
What. A. Weekend! #FutureIsGreen | #IrishRugby pic.twitter.com/KuoUWMGvzW— Irish Rugby (@IrishRugby) March 19, 2023
"I said to you in New Zealand, 'now this was the start of our World Cup year'," Farrell said.
"The most pleasing thing is that we've continued to be successful. To find a way. Everyone was nervous about that except us.
"This is part of the journey, isn't it? Obviously this stands on its own right, as does the New Zealand tour.
"But it's part of the journey of us as a group going forward into a World Cup. Like I said, we'll get two or three months pre-season training for the first time together and I expect ourselves to be better obviously because of that.
“We've carried on winning, is that the yardstick? I don't know.
"We just go on the performances and the performances were pretty good in New Zealand and we've continued to again find a way.
"It's never been perfect, but the game is not like that, so the mental strength of our game and large parts of our game are in a good place.
"There's a long way for us to go for us to be at our best which is a great sign."