Malcolm Turnbull and Bill Shorten have temporarily set aside their differences out of respect for the 18 soldiers killed during the Black Hawk disaster 20 years ago.
A memorial service was held in Townsville on Sunday to commemorate the helicopter tragedy, which was the army's worst peacetime disaster.
Two Black Hawk helicopters collided in 1996 during terrorism exercises, killing 15 Special Air Service Regiment soldiers and three aircrew.
Mr Turnbull said it was a sad anniversary.
"It was a tragic incident," he told reporters in Sydney.
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The Labor leader said it was a very tough time for families of loved ones who were lost.
"I do also wish to acknowledge the remarkable work done by emergency teams, the bravery shown by defence forces, and by local emergency teams," Mr Shorten told reporters in Townsville.
Mr Shorten had earlier laid a wreath before the beginning of the memorial service.
Mr Turnbull would lay a wreath later in the day.
The two had put out a joint statement, saying it was a tragedy for the Australian Army, the Townsville community, the Special Air Service Regiment in Perth and the nation.
The local Member of federal parliament, Ewen Jones, was invited to attend the service and represent the Commonwealth.
There were also services in Sydney and at Campbell Barracks, Swanbourne.
