China will hold naval exercises in the South China Sea on Saturday, its maritime authority said, after a week of recrimination from Western powers over its military ambitions across the Pacific region.

The exercises, set to take place in the sea less than 25 kilometres (15.5 miles) off the coast of south China's Hainan province, come as the United States leads warnings over China's growing military and economic presence in an area spanning from the South China Sea to the Pacific Islands.

"Military exercises will be held and entry is prohibited," the Maritime Safety administration said in a statement Thursday, warning that an area of roughly 100 square kilometres would be closed off to maritime traffic for five hours.

China routinely conducts similar drills in waters near its shores, with an exercise in another area of the sea near Hainan scheduled for next week, as well as multiple others along the country's eastern coastline.

But the latest exercises come as Beijing faces a growing chorus of warnings from the United States and Western allies over its naval ambitions, which critics say are a beachhead for a wider attempt to change the regional balance of power. 

US Secretary of State Antony Blinken on Thursday accused Beijing of raising tensions over Taiwan, which China claims as part of its territory.

"Beijing has engaged in increasingly provocative rhetoric and activity like flying PLA aircraft near Taiwan on an almost daily basis," Blinken said in a speech, referring to the People's Liberation Army.

He also called for efforts to counterbalance China's "intent to reshape the international order."

Blinken's comments followed verbal sparring between Beijing and Washington over President Joe Biden's promise to defend Taiwan if attacked by China, made on the president's trip to the region earlier this week.

China has in turn vowed to defend its national interests over Taiwan, warning Washington not to "underestimate" Beijing's resolve and capabilities on the issue.

Meanwhile, governments including Australia and New Zealand have sounded the alarm this week over leaked documents that appeared to show a plan to build broad security cooperation between China and the Pacific Islands.

But China has said its cooperation with Pacific Island countries "does not target any country," and rejected claims that it is pressuring small states into security agreements.

Australia urges Pacific nations to shun China security deals

Australia urged South Pacific nations to spurn China's attempts to extend its security reach across the region Friday, seeking to fend off a high-level charm offensive by Beijing.

Foreign Minister Penny Wong was in Fiji on her first solo visit, seeking to woo island states after the Solomon Islands took Canberra by surprise last month by signing a wide-ranging security pact with China.

"We have expressed our concerns publicly about the security agreement," Wong told reporters in the capital of Suva.

"As do other Pacific islands, we think there are consequences. We think that it's important that the security of the region be determined by the region. And historically that has been the case. And we think that is a good thing."

In a duel for influence, China's Foreign Minister Wang Yi was flying across the Pacific at the same time to discuss Beijing's plan to dramatically expand its security and economic engagement.

At the first stop in the Solomon Islands Thursday, Wang lashed out at "smears and attacks" against the security pact with the island state, speaking at a news conference in Honiara to which some journalists were excluded.

Wang took a short flight to Kiribati on Friday, the next destination in an extensive tour lasting until June 4 that will also take in Samoa, Papua New Guinea and Fiji.

- 'Partner of choice' -
Australia's foreign minister, who was sworn in Monday shortly after her Labor Party won May 21 national elections, said her country was a better fit than China.

"We want to be a partner of choice," she said.

"We want to demonstrate to your nation and other nations of the region that we are a partner who can be trusted, who can be reliable. And historically we have been," Wong said, pointing to Australia's record on providing development assistance.

"We want to work with you on your priorities. We want to work together as part of the Pacific family," she said.

The Australian minister said she flew to Fiji to demonstrate that the Pacific is a priority, and the timing was not influenced by her Chinese counterpart's trip.

She reiterated that Prime Minister Anthony Albanese's new government aims to reset after a "lost decade" of action on climate change, an existential threat to low-lying Pacific islands. 

Western powers have expressed concern over leaked plans to expand China's influence in the South Pacific.

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.

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

- 'Access and control' -
It would also give China the chance to train local police, become involved in 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.

As details of the Chinese plan emerged, New Zealand Prime Minister Jacinda Ardern said the Pacific could handle its own security without China's help. 

The US State Department warned countries to be wary of "shadowy, vague deals with little transparency" with China.

The Chinese plan, if approved, would represent a significant change, facilitating everything from the deployment of Chinese police to visits by Chinese "art troupes".

Flights between China and the Pacific Islands would increase. Beijing would appoint a regional envoy, supply training for young Pacific diplomats and provide 2,500 government scholarships.

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".