Women's World Cup holders Japan have scored 27 goals in five games but star striker Nahomi Kawasumi is still worried about their third straight Asian Games final against North Korea on Wednesday.

Kawasumi's team have not conceded a goal and they were barely troubled in their 3-0 semi-final win over Vietnam. The US-based striker is still not satisfied.

Nine months from the next World Cup in Canada, Japan's performance will be keenly watched in a final packed with political symbolism.

North Korea are banned from next year's tournament after several players in 2011 failed drug tests, a result they blamed on using traditional musk deer gland medicine after a lightning strike.

But despite the doping controversy, third-ranked Japan know North Korea, with two of the last three Asian Games titles, are not a side to be taken lightly.

"Whether it's South Korea or North Korea, we know we won't easily be able to put three or four past them like we have so far," Kawasumi said of the final.

"We can play a lot better. It's not on any certain individuals, but we're not performing at a world-class level right now. We've had chances, and we need to start taking them."

"We really need to prepare well for the match. We've got to go out and show that we want to win the championship again," added the 29-year-old Seattle Reign player.

While North Korea were embroiled in the doping controversy at the 2011 World Cup, Japan won the title and they went on to take the silver medal at the 2012 London Olympics.

However North Korea, ranked 11th, have no fear of Japan's world-beating 'Nadeshiko'.

They won the 2002 Asian Games final against China, beat Japan on penalties to defend their title in 2006 and only went down 1-0 to their rivals in 2010.

And North Korea reached the final in Incheon with their 13th victory in 15 meetings with another regional rival, South Korea.

Coach Kim Kwang-Min praised the North's women for their fightback after going a goal down against the South, who were playing on home territory.

"We became more aggressive and created scoring opportunities later," he said.

Kim said he wanted to see the same attitude in the final at the Munhak Stadium in Incheon, which saw some momentous matches during the 2002 men's World Cup finals.