SYDNEY : Australia's new government aims to take a more activist "middle power" role in global affairs, Prime Minister Kevin Rudd said ahead of his first major trip abroad Thursday.

In his maiden foreign policy address since sweeping to power in a November election landslide, the centre-left former diplomat outlined the thinking behind his 18-day trip to the United States, Europe and China.

"The truth is that Australia's voice has been too quiet for too long across the various councils of the world," Rudd told the Australia National University's East Asia Forum on Wednesday night.

"That is why during the course of the next three years, the world will see an increasingly activist Australian international policy in areas where we believe we may be able to make a positive difference.

"The new Australian government is committed to the principle of creative middle power diplomacy as the best means of enhancing Australia's national interests," he said.

Rudd left Thursday for his first stop, Washington, where he will confirm to President George W. Bush that Australia's 500 combat troops will be pulled out of Iraq soon.

But he stressed to his audience of diplomats and academics that the United States remained a key ally for Australia, arguing that "the US continues to be an overwhelming force for good in the world."

Rudd has indicated, however, that he believes the close ties between his conservative predecessor John Howard and Bush came at the expense of multilateral engagement in forums such as the United Nations.

The new activist approach "means acting in partnership with our friends in the Asia-Pacific region in organisations including APEC, the ASEAN Regional Forum and the East Asia Summit," he said.

After talks with Bush on Friday, Rudd will meet UN Secretary General Ban Ki-moon to highlight his government's plan for greater engagement with the organisation.

He goes on to meet European Commission leaders in Brussels and will attend a NATO summit in Bucharest before visiting Britain and then China.

- AFP/vm