Head coach Eddie Jones’s men head to the Aviva Stadium on Saturday knowing that victory would land an early blow in their quest to reclaim the crown they surrendered to Dublin last year.
Grand Slam holders Ireland are positioned second in the global rankings behind leaders New Zealand, whom they defeated in Dublin last autumn.
“It’s our aim to win the Six Nations, but first up is Ireland and arguably they are the best team in the world,” Mitchell said.
“If you’re going to play the best team in the world you might as well get into them straight away.
“They’ve deserved all the honours that came their way in 2018. Having them first up makes the challenge even more exciting.
“It’s a challenge that you don’t overthink, instead you walk towards it and embrace it.
“It’s always been tough playing there, but it’s even harder now because they’re a well-coached side.
“They’re very consistent and have a process they’re very confident in.”
On Thursday England will name their team for the first of nine Tests before the World Cup begins in September with the fitness of Brad Shields and Joe Cokanasiga the outstanding concerns.
Owen Farrell has made good progress after undergoing thumb surgery and is on course to lead the team in Dublin, but Shields and Cokanasiga have until tomorrow to prove they have fully recovered from their respective side and knee injuries.
Flanker Jack Clifford has returned home after sustaining a head injury in training.