Barcelona forward Neymar says he is "optimistic" about agreeing a new contract at Camp Nou - but refused to guarantee his long-term future at the club.

Talks over an improved deal with Barca have been rumbling on for a number of weeks despite the Brazil international having three years left to run on his current agreement.

Neymar's father and agent insisted earlier this month that they would agree an extension with the European champions but speculation persists that he could be tempted to move elsewhere.

Bitter rivals Real Madrid and Manchester City, tipped to appoint Pep Guardiola as head coach ahead of next season, have been linked with potential bids.

The 23-year-old says there is no truth in rumours of a move to the Eithad Stadium, but could not give any assurances over his future when speaking to the media at Barcelona airport.

"We're talking about it [my renewal]. I'm optimistic. But I don't know what will happen," he said.