By Nick Byant
BBC News, Sydney
Clashes have broken out on the streets of Sydney between police and anti-war campaigners protesting against the visit of US Vice-President Dick Cheney.
The protesters were trying to march on the US consulate in Sydney
The security situation in Iraq is set to top the agenda in his discussions with the Australian government.
Prime Minister John Howard is under strong pressure at home to announce a withdrawal of Australian forces.
The scuffles broke out when a crowd of protestors tried to march on the US consulate in the centre of Sydney.
They view Dick Cheney as one of the main architects of the Iraq war - a conflict which is becoming increasingly unpopular with the public as a whole.
A poll has suggested that more than two-thirds of the Australian people want Mr Howard to announce a date for the withdrawal of the country's forces, or to order an immediate pull out.
But the Australian prime minister has refused to follow the lead of his British counterpart, Tony Blair, by laying out an exit strategy.
Prior to his trip, the US vice-president had been hoping that Australia would bolster its presence in Iraq, which is currently 1,400-strong.
But Mr Howard, who faces re-election this year, has ruled that out. He has instead offered to despatch 70 military advisers to help train the Iraqi army.
It also seems likely that Australia will double its deployment in Afghanistan, raising the number of soldiers to about 1,000.
The fight against the Taleban and al-Qaeda commands widespread public and political support.