Australia is carefully weighing up a request from the United States to help confront Iran by providing security to trading ships passing through the Strait of Hormuz.

US Secretary of State Mike Pompeo has asked Australia to join America in providing security in the world's most important waterway for oil shipments.

Mr Pompeo and newly appointed US Defense Secretary Mark Esper met with Australia's Foreign Minister Marise Payne and Defence Minister Linda Reynolds in Sydney on Sunday.

"We hope Australia will partner with us on some of the most pressing foreign policy challenges of our time, like efforts to stabilise Syria and keep Afghanistan free of terror, and confront the Islamic Republic of Iran's unprovoked attacks on international shipping in the Strait of Hormuz," Mr Pompeo told reporters.

Senator Reynolds said the government's decision would be based on Australia's sovereign interests.

"We are deeply concerned by the heightened tensions in the region, and we are strongly condemning the attacks on shipping in the Gulf of Oman," she said.

"The request that the United States has made is a very serious one and a complex one. That's why we are currently giving this request very serious consideration.

"No decision has been made."

Iranian commandos seized a British-flagged tanker near the Strait of Hormuz amid increasing tensions with the US and its allies.

Senator Reynolds said the two countries had shared concerns about the threat to freedom of navigation and maritime trade in the Middle East.

Mr Pompeo later told a forum at the State Library of NSW the US had asked "every nation to join" and contribute something different.

"This is a deterrent against the bad behaviour of Iran," the secretary of state said.

"We're asking every nation that has energy needs, that has goods and services passing through, to contribute to our effort."

Mr Pompeo also moved to reassure Australia the United States intended to continue strong engagement in the Asia-Pacific region.

"The United States is a Pacific nation. We care deeply about what happens here and we are here to stay," he said.

"I want Australians to know, they can always rely on the United States of America."