Stronger ties with Japan the priority for Clinton's Asia-Pacific trip

US Secretary of State Hillary Clinton will begin her Asia-Pacific trip with a major speech in Hawaii tomorrow explaining how the United States plans to step up its engagement in the region.

And while the "Pacific" part of the trip will take up most of her time - with visits to Papua New Guinea, New Zealand and Australia - the "Asia" part of the week will be of uppermost concern.

In Hawaii, Mrs Clinton will hold crucial talks with Japanese Foreign Minister Katsuya Okada ahead of the 50th anniversary next week of the US-Japan security pact.

That covenant was described last week as the most important piece of security architecture for the United States in the Asia-Pacific region.

Kurt Campbell, US Assistant Secretary of State for East Asia and the Pacific, said Washington wanted "a very clear set of statements on the part of the Japanese Government and a desire to continue to work closely with us".

Briefing reporters ahead of Mrs Clinton's trip, Dr Campbell said the US-Japan security relationship "has provided the foundation for the American engagement in Asia and, I would argue, has provided the context for an Asia that has been essentially at peace for decades".

"This is a critical alliance. I think we all appreciate and understand that."

US-Japanese relations - and implicitly the security alliance - have been strained since the election last year of a left-leaning Government in Tokyo that advocates a more independent foreign policy and has doubts about the country's commitment to the US Marine base on Okinawa.

A weakened security alliance with Japan at a time that China is in the ascendancy would be a worry to the rest of Asia, Dr Campbell implied.

He said many countries in Asia had said they "very much want a strong US-Japan alliance".

The difficulty with Japan is one of the reasons that the United States, while planning to drop the ban on military exercises with New Zealand - one of the reprisals for our anti-nuclear policy - will not go as far as contemplating resuming naval visits to these shores.

Visits of nuclear-armed warships to Japan are under the spotlight after Prime Minister Yukio Hatoyama ordered an inquiry into whether there had been a secret deal in the past for nuclear-powered US warships to enter his country's ports, contrary to the security pact.

The results of the inquiry are due out this month.

A decision on the Okinawa base is expected by May.

Mr Hatoyama has asked US President Barack Obama to trust him to sort out the base issue.

The last time the United States believes it heard a message like that was in 1984 from the newly elected Labour Prime Minister in New Zealand, David Lange.

It is not surprising the US is stressing the importance of the pact to its interests.