SYDNEY, Sept 5 (Reuters) - The United States is giving Australia more access to top-secret American military technology under a new defence cooperation treaty they signed on Wednesday.

President George W. Bush and Australian Prime Minister John Howard signed a defence trade cooperation treaty "that will strengthen our already robust alliance" a White House statement said.

"Good job," Bush said as he shook hands with Howard after the signing at Howard's office in Sydney.

"The treaty will reduce barriers to the exchange of defence goods, services, and information between Australia and the United States, increasing interoperability and providing our forces with the most effective means to counter new threats," the White House said.

"The treaty will also help our respective defence industries share their rich technical expertise, and increase collaboration and communication between the industries and armed forces," it added.

Australia is a strong ally of the United States and has troops alongside U.S. forces in Iraq and Afghanistan. The Australia-U.S. military alliance is the cornerstone of Australia's defence policy.

But Australia has long complained of U.S. restrictions on the use, manufacture and repair of top-secret U.S. weapons technology and information because of Washington's concerns about keeping the information secure from espionage.

Both countries are negotiating the A$16 billion ($13 billion) sale of advanced F-35 Joint Strike Fighters, while the U.S. recently agreed to Australia buying 24 FA-18F Super Hornet fighters for A$6.6 billion.

Australia is also buying U.S.-built cruise missiles and airborne early warning aircraft for its air force and sophisticated radars for a new fleet of destroyers.

"I think one of the very significant things in this potential (deal) is the arranging for greater access for the Australian military, in its purchase of military hardware, to classified and secret technical information about weapons systems and operations," U.S. ambassador to Australia Robert McCallum told Australian television this week.

The development, he said, would allow Australian and U.S. forces to work more closely together on joint military operations stretching from the Middle East to the Pacific.

AlertNet news is provided by