North Korea's missile tests, the recent spate of terrorist attacks and China's military build-up in the South China Sea are likely to dominate long-awaited talks between Australian and US defence and foreign ministers this week.
Foreign Minister Julie Bishop and Defence Minister Marise Payne will host US Secretary of State Rex Tillerson and Defense Secretary James Mattis - two of the most senior figures in President Donald Trump's administration - for the day-long AUSMIN meeting in Sydney on Monday.
The talks are usually held annually, but it's been nearly two years since the last AUSMIN gathering because elections in the US and Australia in 2016 made it difficult to schedule the high-level talks.
Ms Bishop said this round of talk would be one of the most important in many years.
"The strategic environment is changing rapidly and it's so very important for us to have an insight into the thinking of the new US administration," she told Sky News on Sunday
It also gave an opportunity for Australia to put forward its perspectives and hopefully influence US thinking as the Trump administration reviewed its foreign policy settings, she said.
Observers say that while terrorism is likely to be uppermost in the participants' minds given the recent deadly bombings in Manchester, Jakarta, Baghdad and Kabul, the most pressing issue facing Australia and the US is North Korea's ballistic missile tests.
"The risk is that terrorism has been front of mind for the last couple of weeks, we've had Australians as well as Americans killed," US Studies Centre research fellow Dougal Robinson told AAP.
"So the risk is they give terrorism far more billing than North Korea, which is a particularly important regional issue in Australia's region."
Mr Robinson said the US and Australian officials were expected to discuss contingency operations and potential diplomatic approaches in relation to North Korea, which has sparked alarm across the region by carrying out nine missile tests this year.
The US and Australia have been urging China to put diplomatic and economic pressure on North Korea to end its missile program amid fears Pyongyang's long-range missiles could one day hit the US or Australia.
Pyongyang warned Australia in April that it could be the target of a nuclear weapons strike if it continued to "blindly" follow the US.
Ms Bishop said there was no doubt Mr Trump had changed the dynamics of the discussion, and warned China it was not in its interests to have a nuclear weaponised North Korea.
"It creates huge instability for the region; that's not in China's interests, it's not in anybody else's interests," she said.
But while the US and Australia hope China can persuade North Korea to dump its missile program, they remain concerned by Beijing's construction of artificial islands in the South China Sea.
The US sparked fury from China when a US Navy patrol came within 12 nautical miles of one of the man-made islands last month as it carried out freedom of navigation patrols in the key trade route.
During a visit to Sydney this week, veteran Republican Senator John McCain accused China of being a "bully" and suggested Australia consider joining the US and other Asia Pacific neighbours in future patrols.
Mr Robinson also expects Australian officials at the meeting to stress Canberra's desire for the US to have a broader economic and diplomatic engagement with Asia.
"There's a sense that US engagement in Asia under the Trump administration is very military heavy and that following the collapse of the Trans-Pacific Partnership trade deal and with a proposed budget cut to the State Department of 30 per cent, there are questions both in Canberra and the region about the nature of US engagement in Asia," he said.
