Prime Minister Julia Gillard and US President Barack Obama and are expected to unveil details for greater cooperation between their two countries' forces when the American leader visits next week. The visit, which includes a speech to a joint sitting of parliament in Canberra and a brief sojourn with Australian troops in the Northern Territory, comes as the two nations mark the 60th anniversary of the ANZUS treaty. Defence Minister Stephen Smith today dismissed talk Mr Obama would announce an increased rotation of US marine forces through Darwin, a gateway to Asia, as part of a planned permanent new military presence in the Asia-Pacific region. "There are no United States bases in Australia and no proposal for such bases," Mr Smith said in a statement. Australia is a crucial link in the Pentagon's so-called global force posture review, which Mr Smith said will lead to an expansion of joint training and exercises in Australia. "Our starting point is that it would be an unambiguously good thing to extend such practical cooperation arrangements," Mr Smith said. In Hawaii, Foreign Minister Kevin Rudd urged patience, as defence experts warned that some Asian nations such as China may be concerned by news of a US base in Darwin. "It's important that we await the president's visit before confirming any particular elements of what that defence cooperation may entail," he told reporters attending an APEC forum."Australia has always been transparent with all countries in the region about the importance of this alliance to us and to the broader security of the region." Australian Greens leader Bob Brown said any proposal for a US base should be debated by parliament. "The proposal for Darwin needs to be clearly qualified and quantified by the Gillard government," he said in a statement. The Greens want to end foreign troop deployment, training and hosting on Australian territory. Mr Rudd said the Greens do not direct Australia's national security or foreign policy. "These matters are matters of fundamental national interest in which we, as the Australian government, engage in the deepest analysis and consideration," he said. US forces have been visiting this country's shores since as far back as 1907 and using Australian facilities for 60 years. Marines have for years been involved in rotations of up to several months at a time through Australian Defence Forces bases, including Darwin. About two-thirds of the force is based in the Pacific, including Okinawa. US Defence Secretary Leon Panetta has said his goal is to maintain a strong American presence and ensure nations in the region understand "we are there to stay". Opposition defence spokesman David Johnston said the coalition supported enhanced US access to Australian military bases. "The US is the bedrock of global security and a major force for stability in the Asia-Pacific region," the senator said. Recent AUSMIN talks between Australian and US defence and foreign affairs ministers agreed to a strengthened military relationship. Mr Obama arrives in Australia on Wednesday and will address a special sitting of parliament on Thursday before heading to Darwin with Ms Gillard. THE federal government has reaffirmed plans to step up joint training and military exercises with the US but ruled out the establishment of a Marine Corps base in Australia.