Australian personnel operating a state-of-the-art surveillance plane are filtering information gleaned from the Middle East war to ensure intelligence is not shared with the United States for offensive purposes, the defence force chief says.

As the federal government extended the deployment of the E-7 Wedgetail aircraft on Thursday, the chief of Defence, Admiral David Johnston, said the crew were taking active steps to only contribute to defensive operations.

The prime minister, Anthony Albanese, confirmed the plane would stay in the Middle East beyond its initial four-week mission to the United Arab Emirates after agreement from cabinet’s national security committee.

Intelligence about drones and other airborne threats is being shared with the US, but Johnston said the highly trained crew would withhold information not related to defensive activities.

“That was a really important consideration of the manner by which that aircraft was deployed and the functions it’s performing,” he said at the Russell defence headquarters in Canberra.

“The capabilities of the aircraft are such that it is the operators of that platform who determine what information leaves the platform.

“And we’re able to apply filters to it, draw judgments on the nature of what the aircraft is detecting through all of the means, from radar to electronic systems, and then be very clear on what we are presenting out that is then picked up inside the air operation system.”

Labor has faced criticism for supporting the war being led by the US president, Donald Trump, and Israel’s prime minister, Benjamin Netanyahu, but insists Australia’s role is only defensive.

Ahead of the release of the next national defence strategy next week, Johnston called the E-7 Wedgetail “a gem of an aircraft”.

Approximately 85 defence force members were deployed as part of Australia’s assistance package to the UAE in early March. Albanese would not confirm where in the Middle East the Wedgetail would operate going forward.

“The Wedgetail will be staying in the region for a period of time,” he said, before departing for a visit to Singapore on Thursday.

Asked about possible Australian efforts to help reopen the strategic strait of Hormuz, Johnston said the Royal Australian Navy was equipped to help, but such a move might not be in the country’s strategic interest.

“I am very confident we could deploy a ship into that environment if the government was to make a decision to do so. I have no hesitation in our ability to work in a strait of Hormuz-type role.

“But perhaps what is an at least as important question is: where do our priorities lie?

“The United States has moved enormous military capacity into the Gulf region at the moment, including a lot of capacity out of the Indo-Pacific. This is an important time for us to be present in the Indo-Pacific to maintain that regional environment that we seek to maintain.”

Trump this week criticised Australia for not providing assistance on reopening the strait, which usually carries about 20% of global oil supplies.

Speaking about Nato countries, as well as partners including Australia, Japan and South Korea, Trump said, “they haven’t helped at all”.

The opposition has previously criticised Labor for not sending a warship when former US president Joe Biden was coordinating defensive operations in the Red Sea amid attacks on commercial shipping from Iran-backed militia.

Johnston said on Thursday that decision had nothing to do with maintenance or capability problems, but was rather about strategic priorities.

“We were able to deploy to the Red Sea as much as we are able to deploy to the strait of Hormuz,” he said.