JULIA Gillard received a four-minute standing ovation after making a historic address to a joint meeting of the US Congress in Washington.

During the half-hour address she hardened Australia's military commitment in Afghanistan, telling the Congress Australia remembered America's help in World War II and would always stand by it as "a true friend Down Under".

Conceding that the transition to local control in Afghanistan will take "some years", Ms Gillard threw herself fully behind President Barack Obama's Afghanistan strategy, saying the two nations were inextricably linked by shared values and common aims.

Ms Gillard also challenged the US to use its capacity for reinvention to join Australia in pressing for new rounds of trade liberalisation and economic reform.

Describing herself as a "true mate", Ms Gillard urged the US to "be worthy to your own best traditions," calling on the nation to turn its creativity to addressing climate change.

And she called for US leadership in the Asia-Pacific to balance the rise of China and India and ensure all nations in the region could enjoy the benefits of prosperity and growth.

Ms Gillard's comments came in an address to a joint sitting of Congress to mark the 60th anniversary of the signing of the ANZUS treaty - a military alliance which binds Australia, New Zealand and the US.

Among Australian prime ministers, only Bob Hawke and John Howard have been accorded the same honor, while Robert Menzies addressed the House of Representatives in 1955.

Ms Gillard used her speech to make clear that Americans should expect firm and ongoing support from Australia.

"In both our countries, real mates talk straight," she said. "We mean what we say. You have an ally in Australia. An ally for war and peace. An ally for hardship and prosperity. An ally for the 60 years past. And Australia is an ally for all the years to come."

Ms Gillard said Australia had not forgotten that the US helped defeat the Japanese in World War II. She said the US should expect that Australia would not swerve in its support for the Afghanistan war.

"I have told Australia's parliament in Canberra ... what I told General (David) Petraeus in Kabul ... what I told President Obama in the Oval Office this week," she said.

"Australia will stand firm with our ally the United States. Our friends understand this. Our enemies understand this too."

Referring to her recent visits to the war zone, she said she was convinced the Afghanistan coalition had the right strategy.

However, as she outlined her solidarity on the war, she threw out challenges to the gathered US politicians on the economy and climate change.

Calling for US support for the economic reform process through the G-20, she also appealed for the reignition of the stalled Doha Round of international trade negotiations under the auspices of the World Trade Organisation.

On climate change, she called for continuing collaboration, insisting that the world must find a way to decouple economic growth from growth in carbon emissions.

Turning to security, Ms Gillard noted that political power was shifting towards China and India, and urged the Americans to call on the same courage that saw them provide leadership during the Cold War and to apply it to the emerging new world order.

She also praised former US President Ronald Reagan, describing him as a great figure of American optimism who had displayed the same values she believed would see the US continue to prosper and provide global leadership.

"I firmly believe you are the same people who amazed me when I was a small girl by landing on the Moon," she said. "On that great day, I believed Americans could do anything. I believe that still. You can do anything today."