Roberto Martínez has said Everton must wait until the end of the season to open talks on a permanent deal for Gareth Barry, despite his impressive impact at Goodison Park.

The 32-year-old is flourishing on a season-long loan from Manchester City, who deemed him surplus to requirements last summer and would be open to a nominal fee of around £1m for the midfielder when the transfer window reopens.

Barry is out of contract at City next summer but Martínez insists he will honour an agreement to allow the England international to decide his future as a free agent.

"Gareth has been vitally important in what we have achieved so far this season and I would like that to be the case for many, many years to come, but that is a conversation we are going to have in the summer," said the Everton manager.

"The agreement was for the season and for Gareth to just enjoy his football and I don't want to change that.

I don't think there is a real need. There is trust about what we agreed and all I want now is for Gareth to continue concentrating on his football for the second half of the season. I don't want him thinking about his future, which might distract him from enjoying his football and that was the agreement we had."

Everton have home games against Sunderland and Southampton over the festive period to push their Champions League claims and Martínez believes Barry will make his decision for football reasons next summer.