Sydney  - Relations with Japan are "in first-class working order," Prime Minister Kevin Rudd said Sunday before leaving on a mission to repair the damage done by leaving Australia's best ally in the region off his inaugural 17-day world tour in April.

Rudd will be in Japan for four days, the same amount of time he spent in China on his first big trip abroad, before going on to Indonesia June 12.

"The relationship is in first-class working order," Rudd told local television. "The Asia-Pacific region involves many important states. Japan is critical."

Rudd, a Sinologist and fluent Mandarin speaker who was once a diplomat in Beijing, was accused of snubbing Japan by not making a visit earlier in his seven months as prime minister.

He has also strained relations by threatening to take Japan to an international court over its whaling programme in the Southern Ocean.

"His conduct toward Japan over the last six months has been unforgivable," opposition Liberal Party deputy leader Julie Bishop told national broadcaster ABC. "He seems to have gone out of his way to offend them."

In talks with Japanese counterpart Yasuo Fukuda, Rudd will detail his proposal for an Asian version of the European Union that he dubbed the Asia Pacific Community (APC).

Rudd said that India, not presently a member of the 21-member Asia Pacific Economic Cooperation (APEC) forum, would be a cornerstone member of the proposed APC along with the US, China, Japan and Indonesia.

Rudd said the new body would not replace APEC and the regional Association of South-East Asian Nations (ASEAN) but complement them.

Rudd noted that the establishment of APEC had been seen by some as an impossible dream and that France and Germany had been able to come together in the EU.

He said of the proposed APC: "It's a big idea, it will be controversial. Some people will necessarily not support it."

Rudd floated his APC idea last week, setting a 2020 deadline for the creation of a body he said was essential to ensure regional stability.

Bishop was critical of Rudd, the least experienced of the region's leaders, for taking it upon himself to set an agenda for a region some say Australia is barely a part of.

"To suggest to the Asia-Pacific that Australia with a prime minister who has been in the job for about five minutes is now going to reorganize the architecture of the region without any notification is extraordinary," Bishop said. (dpa)