Everton want to sign Gylfi Sigurdsson from Swansea in the summer

Everton want to sign Swansea midfielder Gylfi Sigurdsson in the summer, according to Sky sources.

Sky Sports News HQ understands the Toffees are hoping to strike a deal in the region of £25m for the Iceland international.

Sigurdsson has been a stand-out performer for Swansea this season and has managed to score nine times in the Premier League despite his side's struggles on the pitch.

Sigurdsson scored a vital equaliser for Swansea against Manchester United at Old Trafford

Everton are likely to face competition from Southampton for the 27-year-old, whose current contract at Swansea runs until 2020.

As well as Sigurdsson, Ronald Koeman is interested in signing Ajax captain Davy Klaassen.

The attacking midfielder has enjoyed an exceptional season, scoring 18 goals in 43 matches and helping Ajax reach the Europa League final.

Ajax captain Davy Klaassen is also a transfer target for Everton

Klaassen, who is an Ajax academy graduate, has won three Eredivisie titles and been capped 11 times by the Netherlands.

On Thursday, Koeman warned midfielder Ross Barkley he had one more week to decide his future.

The England midfielder has one year remaining on his present contract and is yet to confirm whether he will sign a new deal.

"Still one week, time for him to decide. The board is working a long time for Ross to stay for a long period," Koeman said ahead of Friday's match against Watford.

"It's up to the player but we don't wait until August. We need an answer if he will accept the contract or we sign a player."