Jim Chalmers has made the case to his US counterpart to remove American-imposed tariffs, while rebuffing calls to increase defence spending in line with NATO allies.
The treasurer spoke with US Treasury Secretary Scott Bessent on Wednesday, the third time the pair have talked.
Dr Chalmers said he pushed for a deal to remove tariffs on Australian exports into the US imposed by President Donald Trump.
"This was a very positive discussion, a very productive discussion," he told reporters in Brisbane on Wednesday.
"I made our case once again when it comes to trade and tariffs and these escalating trade tensions around the world.
"The global economic environment is very uncertain, very unpredictable and very volatile."
Australian goods are slugged with a 10 per cent tariff to enter the US, while steel and aluminium products have a 50 per cent tariff.
As Deputy Prime Minister Richard Marles represents Australia at the NATO summit in The Hague, it remains unclear whether he will secure a face-to-face meeting with Mr Trump at the gathering of world leaders.
Mr Marles is attending in place of Prime Minister Anthony Albanese, who pulled the pin on a potential trip to The Hague after other Indo-Pacific leaders opted out.
Mr Albanese's planned first face-to-face meeting with Mr Trump, on the sidelines of the G7 summit earlier in June, was cancelled after an escalation in the conflict in the Middle East between Israel and Iran.
Asked if he would meet the US president, Mr Marles said it wasn't yet confirmed.
"It's not specifically on the agenda and I wouldn't want to overstate any of that," he told reporters at the security summit on Wednesday.
"We are in large rooms with lots of people, and these meetings, gatherings like this, end up being pretty fluid in terms of the bilaterals that you end up organising."
NATO countries have agreed to increase defence spending to five per cent of GDP, as the US also puts pressure on allies to boost money spent in the area.
While the US has called on Australia to lift defence spending to 3.5 per cent, the federal government aims to increase it from two to 2.3 per cent by 2033/34.
Dr Chalmers stood by the government's spend despite the boost from allies.
"It's not unusual for our partners and friends around the world to express or have a preference for us to spend more on defence. We are actually already very substantially increasing our investment in defence," he said.
"Obviously we've seen the announcements out of Europe. We're obviously tracking those developments very closely ... but we are already dramatically increasing our investment in defence.
"That's warranted and that's why we're doing it."
