By Tom Blackburn

Chelsea are refusing to give up on their pursuit of signing Everton target Kalidou Koulibaly from Napoli, according to a report.

Manchester City completed the signing of John Stones for a reported £47.5million early on Tuesday, and, in turn, Sky Sports claimed on their transfer centre blog Everton are closing in on Ashley Williams.

The Mail claim Everton are also in advanced talks to sign Sunderland centre-back Lamina Kone, who was seen posing with a fan after travelling down to Merseyside in anticipation of a deal being agreed on Monday.

Everton have also been strongly linked with Koulibaly and the London Evening Standard now claim that the Senegal international is Chelsea’s first choice as they bid to strengthen their defence ahead of the new season.

The report claims the Londoners have had a £42million rejected – made up of £37million plus £5million of add-ons.

But it is said that Chelsea have not given up the chase and will offer an improved deal to Koulibaly, who has made it clear to Napoli that he is not interested in signing a new contract.

It was reported by Sport Italia television expert Ifredo Pedulla on his website last month that Everton had tabled a stunning £46million bid for the 25-year-old centre-back.

Koulibaly would become the most expensive signing in Everton’s history if the reported offer was accepted, comfortably surpassing £28million record signing Romelu Lukaku.

Koulibaly has been at Napoli for two years since joining from Metz for £6.5million, and has now played 60 times in Serie A.

The defender played 33 times in the Italian top flight in the 2015-16 season as Napoli finished nine points behind Juventus in second.

Ronald Koeman has been active in his search for players since arriving at Goodison Park this summer, but has been unsuccessful in the hunt for the likes of Graziano Pelle and more recently Axel Witsel.

In other Everton transfer news, Stan Collymore claims imminent Everton signing is an upgrade on Stones.