Arsene Wenger London - AFP Arsene Wenger marked his 15th anniversary in charge of Arsenal on Friday and said he remains determined to stay at the club until the Gunners are the best side in world football. Wenger has faced the most difficult period of his reign in recent months, with star players Cesc Fabregas and Samir Nasri leaving the club and a string of poor results piling the pressure on the Frenchman. Those problems come against the club's failure to win anything since 2005, and few are betting on Arsenal to end the trophy drought this season, with Wenger's men already nine points adrift of leaders Manchester United. Yet speaking ahead of Sunday's north London derby with Spurs, Wenger insisted he retained the hunger to turnaround Arsenal's flagging fortunes. "The vision is to make this club the best club in the world, it is as simple as that," he said. "To carry through the values we think are important in the game. I'm very proud of the values I defend in the game and we will try to continue to do that." Asked to put a time-frame on his ambition for the club, Wenger replied: "In my life I hope. You may say to me I have to live very long, I don't know. "I want to try to give my best because only the best is acceptable and if I don't manage to do it I am very sad. Like when we had a bad start to the season, it is uncomfortable but we keep going." Wenger earlier Friday received unequivocal backing from the club's American owner Stan Kroenke, who told the Daily Telegraph in an interview that the Frenchman would stay at the club for as long as he wanted to. Wenger later welcomed Kroenke's words of support. "I am grateful he (Kroenke) has confidence in my abilities to sort our problems out because that is not easy to find in football," he said. "I have been very lucky to spend 15 years at this club. I live in the present and the future so I hate to look back. I use the history to improve, that's what I want to do. I am grateful and lucky to have spent so much time at this club."