Dr Mahathir's comment's are supported by the 2016 census, which highlights the shift in demographic trends in Australia. More overseas-born migrants now come from Asia than Europe. China, India, the Philippines, Vietnam, Malaysia and Sri Lanka were all listed in Australia's top 10 countries of birth for the overseas-born population.

Dr Mahathir, who worked against former prime ministers Bob Hawke, Paul Keating and John Howard as they sought membership of south-east regional institutions such as the Association of South-East Asian Nations, said "I think it will happen" when asked if Australia's full membership in the organisation was possible one day.

Australia is currently a dialogue partner of ASEAN. Last year Indonesian President Joko Widodo suggested it could be a "good idea" for Australia to join ASEAN – an aspiration of some Australian politicians for decades. Others analysts argue membership in the association would cost Australia policy autonomy because of its consensus-based approach to decision-making.

Dr Mahathir described the bilateral relationship between Malaysia and Australia as "doing quite well". He said he wanted to visit Australia but "at the moment the program for visiting foreign countries is tight".

The two nations are major sources of trade and foreign direct investment for each other. There are about 150,000 Australians of Malaysian descent in Australia and about 26,000 Malaysian students in Australia.

Dr Mahathir was prime minister of Malaysia from 1981 to 2003 and managed a stunning comeback election win in May 2018 over his former protege Najib Razak.

He defected to the opposition because of concerns over corruption in Mr Najib's government, including the 1MDB scandal. The opposition's victory marked the first change of government in Malaysia, 61 years after it gained independence.

China-US tension 'may flare up'

On economic and military tensions between China and the United States, Dr Mahathir conceded that China "to a certain extent militarised the South China Sea".

Malaysia is one of several south-east Asia nations at odds with China over the South China Sea, as it has a claim over some of those waters.

"China has claimed the whole place without regard for countries in the region," he said, "[but] what is most important is that despite the claim, there has been no attempt to police the area, they don't stop ships to examine [them]."

That meant, Dr Mahathir said, that China had effectively not implemented its claim.

In a clear message to both China and the United States, the two great superpowers that dominate the region economically and militarily and which are locked in disputes over trade and the South China Sea, Dr Mahathir urged "no big warships" be deployed in the region.

"We feel that if you keep sending in warships in order to maintain security, the result will be similar action by the other party. And there may be incidents, accidents, and it may flare up into physical confrontation and that would be bad for the area.

"Our wish is to see no big warships coming into the South China Sea, but we do need some policing and that we can do with small boats."

Malaysia, like much of south-east Asia, relies heavily on China for investment and trade, but it is also a part of the Five Power Defence Arrangements, which include Australia, Singapore, the United Kingdom and New Zealand. Malaysia's Butterworth air force base hosts Australian maritime surveillance aircraft.

Dr Mahathir, Mr Morrison and other leaders are in Thailand for the ASEAN and East Asia summits, where the nations have hopes of a free trade deal between 10 ASEAN member states and six partner states.