Rafael Nadal has admitted that he must improve his performance against Novak Djokovic if he is to defeat the Serbian in the US Open final tomorrow.

Nadal has met the world number one on five occasions this year and is yet to record a victory.

Speaking after his four-set semi-final victory over Andy Murray, Nadal confessed that his record against the Serbian is not good, but believes that he is in good form ahead of the match.

"I think I have played my best match this year here, so I'm really happy to be in the final," the Spaniard said.

"This year I'm not having a lot of luck against him - I've played five finals and lost all of them.

"I haven't found a solution yet but I'll try my best. I'll have to be very solid with my serve. New York, help me this time!"

Nadal was victorious at Flushing Meadows in 2010.