Dutton expects Iran to dominate US visit

Peter Dutton expects Scott Morrison and Donald Trump to focus on combating Iranian aggression in the Middle East when the two leaders meet in Washington.

After blaming Iran for bombing attacks on Saudi oilfields, the US has ordered new sanctions against the republic.

Mr Dutton said it was "a very crucial period" to concentrate on the Middle East.

He expects Iran to be the centrepiece of the prime minister's discussions with the US president and secretaries of defence and state.

Australia is taking part in a US-led mission to protect oil ships from Iranian strikes in the Strait of Hormuz.

"If we see a disruption there, then we'll see a spike in prices at the bowser here," Mr Dutton told the Nine Network on Friday.

"So it's in our national interest to make sure that there is free trade, free movement of those oil tankers."

The US president says he has evidence that Iran was behind the attacks on the Saudi oil facilities last weekend.

Defence Minister Linda Reynolds said the Australian government was "highly concerned" about the incident.

"But we are still assessing information," she told ABC radio.

"We are in close contact with our allies and also our embassies in the region. We haven't yet made any public attribution. I am certain this will be a topic of discussion for the prime minister's visit to the United States."