Western powers sounded the alarm Thursday over leaked plans to dramatically expand China's security and economic reach in the South Pacific, in what one regional leader called a thinly veiled effort to lock island states into "Beijing's orbit".

If approved by Pacific island nations, the wide-ranging draft agreement and a five-year plan, both obtained by AFP, would give China a larger security footprint in a region seen as crucial to the interests of the United States and its allies.

Foreign Minister Wang Yi rejected Western criticism of Beijing's deepening engagement in the Pacific as he launched an eight-nation tour to present the potentially lucrative offer.

"China's cooperation with Pacific Island countries does not target any country," he said in the Solomon Islands' capital Honiara, while warning other countries not to interfere.

"All the Pacific island countries are entitled to make their own choice instead of being just mere followers of others," he told journalists.

The Chinese package would offer 10 small island states millions of dollars in assistance, the prospect of a China-Pacific Islands free trade agreement and access to China's vast market of 1.4 billion people.

It would also give China the chance to train local police, become involved in local cybersecurity, expand political ties, conduct sensitive marine mapping and gain greater access to natural resources.

The "comprehensive development vision" is believed to be up for approval when Wang meets regional foreign ministers on Monday in Fiji.

- No help needed -

"This is China seeking to increase its influence in the region of the world where Australia has been the security partner of choice since the Second World War," Australian Prime Minister Anthony Albanese said.

Australia "needs to respond", he said, outlining a "step-up" in Pacific engagement with extra money for defence training, maritime security and infrastructure to combat the effects of climate change.

Australian Foreign Minister Penny Wong flew to Fiji on the same day her Chinese counterpart began his Pacific tour.

Under the new Australian government there would be no more "disrespecting" Pacific nations or "ignoring" their calls to act on climate change, she said in the capital Suva.

In a barb seemingly directed at Beijing, she added: "We don't seek to create unsustainable debt levels."  

New Zealand's Prime Minister Jacinda Ardern said the region had no need for Beijing's security arrangements.

"We are very strongly of the view that we have, within the Pacific, the means and ability to respond to any security challenges that exist, and New Zealand is willing to do that," she said after a meeting with US senators in Washington.

US State Department Spokesman Ned Price warned the countries in question to be wary of "shadowy" agreements with China.

- 'Mass surveillance' -

The Chinese plan, if approved, would represent a significant change, facilitating the deployment of Chinese police and increased flights between China and the Pacific Islands. 

Beijing would appoint a regional envoy, supply training for young Pacific diplomats and provide 2,500 government scholarships.

"It's relatively rare paper evidence of China's ambition to establish itself as a regional security power," said Mihai Sora, Pacific foreign policy analyst at the Sydney-based Lowy Institute.

The Chinese plan is also raising alarm bells in regional capitals.

In a stark letter to fellow Pacific leaders, Federated States of Micronesia President David Panuelo warned the agreement seems "attractive" at first glance, but would allow China to "acquire access and control of our region".

Calling the proposals "disingenuous", Panuelo said they would deliver Chinese influence over government and industries, and allow "mass surveillance" of calls and email.  

- Lucrative -

Micronesia has a compact of free association with the United States, making it one of the region's closest US allies.

But other Pacific leaders may see the Chinese proposal as possibly lucrative or beneficial.

Policymakers in the United States, Australia, New Zealand and Japan are still reeling from revelations in April that the Solomon Islands secretly negotiated a security agreement with Beijing.

A leaked draft of the agreement contained a provision allowing Chinese naval deployments to the island nation, which lies less than 2,000 kilometres (1,200 miles) from Australia.

Solomon Islands has said it will not host a Chinese military base but Honiara is also prohibited from speaking publicly about the deal without China's permission.

During his visit to the Solomon Islands, Wang stressed Beijing had "no intention at all" to build a military base in the island state.

Wang signed a series of agreements with Solomon Islands, according to the island state's Foreign Minister Jeremiah Manele, including one on maritime investment. 

A leaked draft of the maritime deal, details of which have not been made public, showed it covers undersea cables, port wharves, shipbuilding and other areas.

The pair also discussed a possible project to build a police training centre, Manele said.

Travelling until June 4, Wang will also stop in Papua New Guinea, Fiji, Kiribati and Samoa, as well as hold video calls with Micronesia and the Cook Islands -- a self-governing part of New Zealand.