Beleaguered manager Arsene Wenger believes his Arsenal side can continue to fight for trophies to the end of the season, despite struggling in the Premier League and already being 2-0 down to Barcelona ahead of the second leg of their Champions League last-16 tie.

Wenger's Arsenal, who have not won the Premier League since 2004, were in a good position to fight for three trophies just a month ago, but one win in the last seven matches has seen them dumped out of the FA Cup by Watford, lose ground on surprise Premier League leaders Leicester City and lose to Barcelona at home in the Champions League. However, Wenger promised to keep fighting.

"We fight, of course, to win trophies and at the moment we are not favourites to deliver that but no matter how big the chance we have – I think the Premiership is quite open, much more than people think it is – and in the Champions League at the moment we have a very small chance. But, let's give our best tomorrow (Wednesday 16 March) – you never know," said the Frenchman to reporters at a news conference.

Wenger, who has been in charge of Arsenal since 1996, has been under increasing pressure from the Arsenal fans and pundits who, with Chelsea and the two Manchester clubs struggling for form, saw this season as their best chance of winning the title in years. However, Wenger maintains his desire to stay at the club and said his motivation is as strong as ever.

"I have no doubt about my huge motivation. I just think that I have built the club in a way – I did it with hard work, without any external resources and I think that if you compare the club from the moment I arrived to the club where it is today, we have moved forward and without any money from anybody, just the money produced from the quality of our work," he said.

"I am even more motivated than the first day that I arrived and I feel more the pressure and the responsibility to keep at this club and move it forward. The problem when you are a long time somewhere is that you are always questioned about the duration. I personally don't question my dedication, it is absolutely 100% and I think I give more time to my club now than when I arrived."

To progress to the Champions League quarter-finals, Wenger's Arsenal will have to do something nobody has ever done before – overturn a 2-0 deficit from the first leg at Barcelona's Camp Nou.