US Defense Secretary James Mattis says America and Australia are united in their resolve to take on terrorists and won’t be scared off.

Speaking at the start of the high-level talks with Australia’s foreign and defence ministers, Mr Mattis said the US did not take its alliance with Australia for granted and wanted it to strengthen, particularly when it comes to taking on terrorists.

“We are united in our resolve even against an enemy that thinks, by hurting us, they can scare us. We don’t scare,” he told the meeting in Sydney on Monday.

“We are here to work together in a manner that protects the freedoms and the values we share together and we’re committed to passing those freedoms on to the next generation intact.”

Mr Mattis has joined US Secretary of State Rex Tillerson for the AusMin talks hosted by Australia’s Foreign Minister Julie Bishop and Defence Minister Marise Payne.

The talks follow the latest deadly terrorist attack in London at the weekend, when three armed terrorists mowed down pedestrians on London Bridge before stabbing people in nearby Borough Market.

Three Australians were caught up in the melee.

Terrorism is expected to be discussed during the one-day meeting, along with the increasing threat posed by North Korea’s nuclear missile program and growing regional tensions about China’s militarisation of artificial islands in the South China Sea.

Mr Tillerson said he was looking forward to discussing ways the US and Australia could promote their shared commitment to the values of freedom, democracy, and a rules-based order for the world.

He said that commitment had been cemented not only by both nations fighting alongside each other in major conflicts, but the “common fight we share against the most heinous of actions we have seen, most recently in London yet again”.

Mr Tillerson said ways to strengthen economic and trade relations between the US and Australia were also on the agenda.

There has been growing concerns in the Asia-Pacific region about the US and trade, given President Donald Trump’s decision to pull out of the Trans Pacific Partnership.

The AusMin talks are usually held annually but it’s been nearly two years since the last gathering because elections in the US and Australia in 2016 made it difficult to schedule the high-level talks.

– AAP