It is vitally important a Donald Trump-led America remains engaged in the Asia-Pacific and meets the challenges of China, Russia and North Korea head on, Australian ambassador to the US Joe Hockey has told an audience in California.
The former Australian treasurer said China and Russia would attempt to fill any void in the region if the US, with Mr Trump as president, made a retreat.
Alliances between the US, Australia, Japan, South Korea and other nations have been built on mutual security and economic interest, but with Mr Trump vowing to scuttle the proposed 12-nation Trans-Pacific Partnership and weaken partnerships the bonds have been tested.
"What has happened in the recent election campaign is for the first time arguably in 98 years the United States has started to confuse its allies," Mr Hockey, speaking at Stanford University, said on Monday.
Mr Hockey described Mr Trump's decision to pull the US from the TPP during his first day in office as an immense disappointment.
The TPP was hatched between the US under President Barack Obama with Australia, New Zealand, Japan, Canada and seven other countries.
"The TPP was more than a trade agreement," Mr Hockey said.
"It was a strategic partnership."
Mr Trump has said he will use his business skills to negotiate better trade deals for the US.
Without the US involved in the TPP the deal will likely die, but there have been calls for it to be renegotiated to appease Mr Trump.
Mr Hockey, however, said Australians and other nations would not accept Mr Trump crowing publicly he had secured a better deal for America.
"The idea that we are going to renegotiate the TPP is quite fanciful because frankly we all have domestic pressures," Mr Hockey said at the event co-sponsored by the US-Asia Security Initiative and Southeast Asia Program at Stanford's Shorenstein Asia-Pacific Research Center.
"So those pressures wouldn't get easier if in a very celebrated way the president of the United States says 'We got a better deal' because that means we got a lesser deal.
"So if the US gets a better deal out of the TPP then the other 11 countries have to make sacrifices and those other countries are going to find it politically impossible to sell it domestically that they are making more sacrifices than President Trump.
"It's as simple as that."