Australian Prime Minister Julia Gillard says the recent deaths of four servicemen in Afghanistan will not deter the country in its mission to support the U.S.-led war against the Taliban and al-Qaida.

Ms. Gillard defended the country's presence in Afghanistan Tuesday when she and Air Chief Marshal Angus Houston, the head of Australia's defense forces, announced the death of a 23-year-old soldier who was killed during a firefight in the southern province of Helmand. He is the fourth Australian soldier killed in Afghanistan in the past two weeks, and the 27th killed in action during the 10-year-old conflict.

The prime minister told reporters she could not promise Australians “there will be no more hard days.” But Ms. Gillard insisted Afghanistan “is not an endless war,” and “is not a war without purpose.”

About 1,550 Australian troops are stationed in Afghanistan on a mission to train Afghan forces to take over security from U.S. and NATO forces by 2014. Public support for the mission has steadily declined, but Houston said the country has begun “making the best progress” ever against the insurgents.

Houston said the recent death occurred during a raid with Afghan forces that destroyed a large cache of weapons, explosives and ammunition.