Gareth Southgate insists England's group-stage form 'irrelevant' ahead of Slovakia

Boos greeted the end of the 1-1 draw with Denmark and stalemate with Slovenia but England won Group C having started with a 1-0 victory against Serbia.

"Everything that's happened is now pretty irrelevant," the England boss said. "We have things we can build on but this is also a different test, a different phase.

"Each game takes place on its own merit and can take a wild direction at times. This is the exciting part and it's the bit nobody can predict.

"We need to find our next level, which I believe we can. Slovakia are a very well-coached team and they've got a clear playing identity."

Southgate knows improvements are needed against Slovakia and, the nation hopes, beyond, but he says the "squad have reacted very well" after an underwhelming group stage.

"It wasn't tighter than we thought, we knew that all four teams could take points off each other," he said. "It highlights the level of European football really.

"We haven't hit the level yet but we have topped the group and now we have to improve faster than the rest of the teams basically."

Slovakia head coach Francesco Calzona believes England have the best squad at the Euros and could become "unbeatable" if they start to play as a team.

"I think that when England will give great performances as a group they will become unbeatable," Calzona said.

"We need to make the most of everything that they could concede, but we need to be very careful because they have a top-quality squad.

"I think that they have the best squad of the Euros because they have physicality, technique and also creativeness."