WASHINGTON -- Australia's top diplomat on Wednesday accused former NSA analyst Edward Snowden of "unprecedented treachery" for his leaks about secret government surveillance, and offered a staunch defence of her nation's intelligence co-operation with America.

Snowden's revelations prompted President Barack Obama last week to order new limits on how U.S. intelligence officials access the phone records of Americans. But they've also embarrassed Australia, a close U.S. ally. Documents Snowden provided alleged Australia bugged the phone of the Indonesian president.

Speaking at a Washington think-tank , Foreign Minister Julie Bishop welcomed the Obama administration's review of surveillance operations, saying said it was important to make the public case for intelligence work as it saves lives. But she said Australia's government remains satisfied with the oversight of its own intelligence activities.

Bishop launched a stinging attack on Snowden, saying he "continues to shamefully betray his nation while skulking in Russia."

"This represents unprecedented treachery - he's no hero," Bishop said at the Center for Strategic and International Studies. "Snowden claims his actions were driven by a desire for transparency, but in fact they strike at the heart of the collaboration between those nations in world affairs that stand at the forefront of protecting human freedom."

Snowden's defenders say he exposed U.S. government over-reach and struck a blow for individual freedoms and openness through his revelations on massive data collection by intelligence officials and the surveillance of foreign leaders, including U.S. allies.

Bishop said intelligence co-operation with the U.S. would remain a core part of the alliance with Australia. She said collection of intelligence was a duty of democratic governments in protecting their citizens and combating terrorism.

The foreign minister also reiterated Australia's strong support for the Obama administration's foreign policy shift toward Asia-Pacific after more than a decade of war in Afghanistan and Iraq -- conflicts where Australia also fought.

She said the world is feeling the "reverberation" of China's rise and stressed the need to calm tensions in East Asia, where China is locked in a bitter territorial dispute with Japan, and where both China and South Korea are at odds with Japan over its wartime and colonial past.

Bishop is making her second trip to Washington in as many months, after assuming her portfolio in September under new conservative Prime Minister Tony Abbott.

She has met on this trip with National Security Adviser Susan Rice and is meeting Wednesday with Vice-President Joe Biden.