Anthony Albanese, Australia’s prime minister, has been caught on a hot mic joking with a White House official about going “halvies” to fund a Pacific security plan.

Mr Albanese played down his remarks to the US deputy secretary of state as a “jovial” and “friendly” conversation with “a mate of mine”.

But it has raised suspicions that Australia’s £206 million multi-national regional police force, announced on Wednesday, is in fact part of a wider US-backed geopolitical strategy to edge China out of the Pacific and diminish its influence there.

US-China relations have been framed during the Biden administration by rising military and economic competition and friction over Beijing’s threats against democratic Taiwan, its territorial claims in the South China Sea and US accusations of Chinese support for Russia’s war in Ukraine.

However, suspicion of each other’s intentions run deep between the two nations, and the latest video of an unguarded chat between Mr Albanese and Kurt Campbell, on the fringes of a major forum of Pacific leaders in Tonga, is likely to feed into a long-held narrative in Chinese state media of Australia acting as “deputy sheriff” to Washington in the region.

“We had a cracker today getting the Pacific Policing Initiative through. It’s so important. It will make such a difference,” Mr Albanese was heard telling Mr Campbell in a video published by a New Zealand journalist.

The US official replied: “It’s great... I talked to Kevin about it and we were going to do something and he asked us not to, so we did not. We’ve given you the lane, so take the lane.”

The Australian leader responded with a light-hearted quip: “You can go halvies on the cost if you like. It will only cost you a bit.”

Mr Campbell’s comments, in particular, have raised questions about whether Canberra and Washington have been coordinating their actions on security in the Pacific or whether a similar US plan had been derailed.

In a later press conference, Mr Albanese told journalists to “chill out” and brushed aside the idea that the US had been planning to create a Pacific police force or that “Kevin” – presumably a reference to Kevin Rudd, the Australian ambassador to the US – had talked them out of it.

The fallout from the video distracted attention from Australia’s flagship regional policing plan to improve training and create a multinational crisis reaction force of about 200 officers, which was endorsed by Pacific leaders at the summit.

The plan would set up four training centres across the Pacific with a separate hub in the Australian city of Brisbane and was announced by Mr Albanese as he was flanked by the leaders of Tonga, Fiji, Papua New Guinea, and Palau.

Australia and New Zealand have long been at the forefront of security support for the region, leading peacekeeping missions and training for Pacific Island nations, but China has in recent years stepped up its own security ties as it expands its economic, military and diplomatic footprint.

A secretive security pact with the Solomon Islands in 2022 triggered alarm in western capitals that it could pave the way for a Chinese naval base within easy reach of Australia’s coastline.

The Australian policing initiative has been viewed as an effort to put China on the back foot over its plans to boost regional law enforcement, although some Beijing-friendly Pacific leaders raised concerns that Canberra should not seek to bolster its own strategic interests by cutting China out.