DONALD Trump is fundamentally uninterested in alliances that were previously cherished by the US, including its close relationship with Australia, according to Washington insiders.

World leaders trying to find a path forward with the US President should remember he has also shown disdain for “core liberal values”, says foreign policy guru Jake Sullivan, a former key aide for Clinton and Obama.

“The idea alliances are obsolete is a basic instinct of Trump’s that lines up with the argument China has been pushing for years,” Mr Sullivan told the Lowy Institute in Sydney during his lecture on American Strategy in the Asia Pacific on Tuesday night.

“He fundamentally rejects what has been at the core of US foreign policy, that the US agenda can be advanced at same time as others. He thinks if someone else is doing well, they’re taking us for a ride.

“The erosion of alliances is in my view a brutal blow to American leadership.

We should be doubling down on our alliances, using them to face the challenges of the 21st Century.”

Mr Sullivan said that such an attitude was a “cause for alarm”, and placed “more demand and strain” on vital institutions including NATO and could damage America’s relationships in the Asia Pacific to the extent that allies “come to believe they can’t trust” the US.

But Mr Sullivan, who at just 40 years old has become a key figure in US politics, said there was no point in trying to approach the former reality star like a conventional president.

“Trump generally likes authoritarian leaders more than democratic ones,” said Mr Sullivan, when asked how Malcolm Turnbull should approach his already awkward alliance with the 70-year-old. “He sees them as annoying.

“Lecturing Trump on the importance of the Paris climate agreement and pushing him hard on the issue as the European leaders did at the G7 is not a successful strategy. Coming in the back door is probably a better way to go.”

The key to dealing with the President’s protectionist, us-and-them stance is “not to give in to a zero sum conversation but getting Trump to see something in it for him”, says Mr Sullivan.

“Trump responds very well to praise. When people say nice things about him, he thinks nice things about them.”

For Mr Trump, added the policy expert, it was all about seeing offers that had a “tangible benefit” for him. That might be investment converted into American jobs, China’s support on the North Korea issue or Turkey dealing with the Islamic State.

Mr Sullivan said one major concern was how Mr Trump’s “conspicuous rejection of core liberal values” would “affect the advancement of human rights.”

The visiting American, who will meet with key Australian policymakers during his trip, noted that the 70-year-old was not particularly interested in addressing Rodrigo Duterte’s violent outrages in the Philippines, intolerance in Thailand or marginalisation of the Rohingya in India.

All Mr Trump is concerned about is having partners to work with, but Mr Sullivan warned this could lead to “brittleness, fragility in the system and instability of regional order.”

As one of Hillary Clinton’s closest campaign advisers, he confessed he still lies awake at night and wonders what could have been done differently to get them over the line, with just over 70,000 votes between the President and runner-up in three key states.

“There have been a lot of times recently in American and world politics when I’ve not been sure whether the appropriate reaction is to laugh or cry,” he said.

“I’m still in a place where I’m pretty dejected and disillusioned about what’s happening in our country.

“There are aspects of it I find deeply disturbing.”

While he “hadn’t lost all confidence” after the election of Barack Obama eight year ago, Mr Sullivan admitted “you can’t spend two years watching all these horrors unfold and not come away pretty bruised and battered.”

He said he believed there was still hope for the future, but that America’s standing and positive, liberal influence on the world had taken a heavy blow.

“While I think American culture is resilient, I think we are seeing degradation of it,” he said. “People need to stand up and make sure we are defending our institutions.”

He said he hoped the world would see the US for what it is, “a big, complex messy place that’s bigger than any one person or any one president”, and that we could face up to our “collective challenges” in unity.

“Likeminded people in democracies across the world need to come together to find solutions so we can produce a better future for ourselves and our children.”