Everton are determined to hang on to England defender John Stones after emphatically insisting he is not for sale.

Reports emerged of a £20million bid from Chelsea for the 21-year-old, currently in Singapore with the club for the Barclays Asia Trophy.

However, Press Association Sport understands Everton's response is a categoric rejection, with manager Roberto Martinez intent on building a team.

At a sponsor's event last night Stones himself said: "I am very happy at Everton.

"My aim right now is to try to nail down a regular spot in this Everton team and hopefully that will take care of playing for England.

"I have to keep learning from the likes of Phil Jagielka and keep progressing at this club."

Martinez underlined his determination to hang on to his best players after dismissing speculation midfielder James McCarthy could be destined to leave Goodison Park for a bigger club.

"James McCarthy is a phenomenal asset," he said..

"We spent a huge amount of money to bring him to our football club, we're going to build a team around him and he's got a long-term contract with Everton.

"James enjoys his football and is an example for our group. As I said, we're going to build the future around him."

Martinez also brushed off suggestions he was on the brink of signing Jonny Evans from Manchester United.

The Spaniard does need reinforcements in central defense after Sylvin Distin and Antolin Alcaraz left the club this summer but he is prepared to give under-21 player Brendan Galloway a chance to prove himself as cover if necessary.

"It's not true, there's nothing (in that)," he told a press conference in Singapore.

"I always said I'm not going to be commenting publicly on any of the names that have been shared around but I can tell you clearly that there is nothing true in that story."