Eddie Jones says Ireland are the world's most "cohesive" side and has branded them favourites for Saturday's Six Nations game at Twickenham.
The England head coach praised Andy Farrell, who has led Ireland to 10 wins in their past 11 games.
However, Ireland have not won Twickenham under Farrell, losing on both visits.
"Ireland are favourites for the game. They've been in very good form [from] autumn, very settled team," Jones said.
"They're well coached by Andy Farrell. They are literally, and I say that without any hesitation, the most cohesive side in the world."
Ireland's last win at Twickenham came in 2018 when they sealed the Grand Slam.
Both sides remain in contention for this year's title, having won two of their opening three matches but know defeat on Saturday is likely to end their championship aspirations.
"Three teams left to win it and we're lucky to be one of those three," said Jones.
Ireland ended a run of four straight defeats against England 12 months ago with a dominant display in Dublin, but have lost each of their past three visits to Twickenham.
They had won nine games in a row before falling to Grand Slam-chasing France in a barnstorming game in Paris that was followed by a comfortable victory over Italy, who ended the game with 12 men.
"The bulk of their team train together for the bulk of the year. They're very well co-ordinated in attack, very structured, very sequenced in set-plays and they're tough around the breakdown," continued Jones.
"They pose a great challenge for us but we're looking for the challenge. We're not intimated by any team and we're looking forward to playing against them.
"They move the ball at good pace. The secret to any attack is to move the ball at pace with accuracy."
Iain Henderson's return to the squad, after missing the Italy game because of Covid-19, provides a welcome boost for an Irish pack that will be without first choice loosehead prop Andrew Porter, who sustained a tournament-ending ankle injury last time out.