Everton are in advanced talks to sign Sunderland defender Lamine Kone, sources close to the Merseyside club have told ESPN FC.
Everton have agreed a £12 million fee with Swansea for Williams with the Wales captain travelling to Merseyside for talks and a medical.
Sources have also told ESPN FC that Everton are offering Sunderland £17m for Senegal international Kone.
Sunderland have been battling to keep hold of Kone this summer after his impressive performances last season helped the club secure Premier League survival in the second half of last term.
Sunderland had offered Kone a lucrative new deal to try and fend off the interest from Everton, but it appears the Goodison Park outfit are determined to land the 27-year-old.
Sunderland signed Kone for £5m from Lorient in January and selling him would represent a huge profit and allow David Moyes to strengthen his squad elsewhere.
Everton are also closing in on a deal for Crystal Palace forward Yannick Bolasie.