Australia says it will join US-led defence effort in Strait of Hormuz

Australia will join the United States in a coalition of countries protecting oil tankers and cargo ships from threats posed by Iran in the Strait of Hormuz, Prime Minister Scott Morrison said on Wednesday.

"This destabilising behaviour is a threat to Australia's interests in the region," Morrison told a news conference in Canberra.

"The government has decided that it is in Australia's national interest to work with our international partners to contribute. Our contribution will be limited in scope and it will be time-bound," he said.

Morrison said Australia will send a P-8A Poseidon surveillance plane to the Middle East for one month before the end of 2019, while an Australian frigate will be deployed in January 2020 for six months.

Australia's deployment will expand U.S-led efforts to secure the strait, which lies between Oman and Iran and through which almost a fifth of the world's oil passes, after tensions spiked between Iran and Britain.

Washington, which has by far the strongest Western naval contingent in the Gulf, has been calling for its allies to join it in an operation to guard shipping.

However, European countries, which disagree with a U.S. decision to impose sanctions on Iran, have been reluctant to sign up to a U.S.-led mission for fear of adding to tension in the region.