Japan and Korea host crunch matches against Saudi Arabia and Bahrain respectively, while the Australians, who are competing in the Asian qualifiers for the first time, take on DPR Korea in chilly Pyongyang.

It has not have been the smoothest of campaigns for Japan but a point against the Saudis at the National Stadium in Tokyo will give them a spot in the Olympics for a fourth consecutive time.

The Japanese are two points clear of the Saudis but while a draw would be enough to send Yasuharu Sorimachi's side through, the Japanese coach wants his side to go all out for a victory on Wednesday.

"We would like to prepare to play a solid game against them. We are not going for a draw," said the Japan U-23 coach.

"We'd like to bring good news to Mr Osim," added Sorimachi, who is also an assistant to Japan national coach Ivica Osim, who is recovering at a Chiba hospital after suffering a stroke last weekend.

A draw would also suit the Koreans for their Group B match against Bahrain at the Ansan Wa Stadium but after successive goalless draws and a disappointing return of four goals in five games, coach Park Sung-hwa is looking for improvement by his side.

"We are aiming to win this game," said Park. "We haven't been at our best recently but are still top and still unbeaten. We have already showed that we are more than capable of getting the three points.

"Our strikers have to show more movement and give more options to the players who are passing the ball.

"We need to think more about our positioning and what is happening on the pitch."

Korean hopes for a sixth successive Olympic appearance next summer will be helped by the wintry conditions in Ansan, a satellite city of Seoul, which has been shivering in sub-zero temperatures.

"The colder the better," said midfielder Oh Jang-eun. "Players from Middle Eastern nations like Bahrain are not at their best in cold weather. This is an advantage for us."

The conditions will be similar in Pyongyang, where Australia will also be eyeing a sixth straight appearance at the Olympics.

Australia are three points clear of Iraq in Group A after their 2-0 win over the Middle Eastern side in Gosford last Saturday but coach Graham Arnold will be wary of the sub-zero temperatures and the artificial surface at the Kim Il Sung Stadium, which could cause a slip-up by his team.

"It's another big challenge for these players, who have played in six different countries in Asia and are now going into North Korea to play in freezing cold conditions, on artificial grass," he said.

"These are two hurdles for us, but I am very confident that we will be okay."

A loss for the Australians could open the door for the Iraqis, who face Lebanon in the day's other Group A match in Doha.

There are two other games on Wednesday with Syria hosting Uzbekistan in Group B and Qatar facing Vietnam in Group C.