"This destabilizing behavior is a threat to Australia's interests in the region", Morrison told a news conference in Canberra.
"The government has decided it's in Australia's national interests to work with our global partners to contribute to an worldwide maritime security mission ... in the Middle East".
Tension in the region increased when the United Kingdom seized an Iranian oil tanker off Gibraltar last month, prompting Iran to retaliate by seizing a British tanker in the Persian Gulf.
Australia has committed a frigate, surveillance and patrol aircraft and personnel to the Middle East as part of the US-led mission, known as the worldwide maritime security construct (IMSC).
Morrison said Australia would send a P-8A Poseidon surveillance plane to the Middle East for one month before the end of 2019, while an Australian frigate would be deployed for six months from January. A third of the world's liquefied natural gas and nearly 25% of total global oil consumption passes through the 167-kilometre long stretch of water.
India's 2nd Moon Mission enters lunar orbit The Lander would have to decrease its velocity from 6km/second to zero in a controlled, but autonomous manner. Over the next 12 months, the orbiter will study the moon's outer atmosphere and map the lunar surface .
The Strait of Hormuz is the only sea passage from the Persian Gulf to the open ocean.
"(The G7 meeting) is an important time, I think, to reinforce these shared values in today's world - democracy, respect for human rights, worldwide law and free markets", he told reporters. "Our contribution will be limited in scope and it will be time-bound", Morrison said, expressing concern about security incidents in the vital shipping lane in the past few months.
The deployment raises questions about the rules of engagement, and what Australian troops will be able to do in response to any aggressive behaviour that comes their way.
The Prime Minister discussed the contribution with US Secretary of State Mike Pompeo this morning. Iran retaliated by capturing a British oil tanker on July 19.
Washington has lately adopted a quasi-warlike posture against Tehran, and intensified its provocative military moves in the Middle East, among them the June 20 incursion of advanced US-made RQ-4 Global Hawk into Iranian airspace over territorial waters off the coastal province of Hormozgan.