Canada's trade and foreign affairs ministers are meeting with their Pacific Rim counterparts Wednesday in Sydney, Australia, as part of the Asia-Pacific Economic Co-operation summit.

David Emerson and Maxime Bernier will be at ministerial meetings Wednesday and Thursday at the Sydney Opera House overlooking the city's scenic harbour before Prime Minister Stephen Harper's arrival later this week.

The ministers from 21 countries are expected to discuss key issues such as the stalled World Trade Organization negotiations, the formation of a Pacific-wide trade pact, climate change, energy, APEC reform and security. 

In 2006 nearly 85 per cent of Canada’s international trade, or $707 billion, was with APEC member economies, according to Foreign Affairs. Four of Canada’s top five trading partners — the United States, China, Japan and Mexico — are APEC members.

Authorities in Sydney have implemented unprecedented security measures, including 5.5-kilometre steel-and-concrete fence to protect delegates from terrorist threats, as well as the thousands of demonstrators expected to descend upon the city.

Some 3,500 police and 1,500 counterterrorism and special forces have been deployed for the weeklong conference.

Harper is scheduled to participate in APEC meetings over the weekend. He will then pay an official two-day visit to Australia, where he'll be the first Canadian prime minister to address that country's Parliament.

U.S. to 'hang in there' in Iraq: Bush

Meanwhile Wednesday, U.S. President George W. Bush and Australian Prime Minister John Howard reaffirmed their alliance ahead of the conference, with the Australian leader pledging his commitment to keep Australia's 1,600 troops in Iraq.

Bush also pledged to "hang in there" with Iraqis, despite calls from U.S. Congress to get troops home, and has so far given no indication he plans to reverse the buildup of 30,000 extra U.S. troops.

"There's more work to be done, but reconciliation is taking place," Bush said Wednesday standing alongside Howard, a staunch U.S. ally during the Iraq war.  

Howard has said global warming will be a top priority at the APEC meeting. However, the group's 21 members — which include China, the United States and Russia, the world's top three greenhouse gas emitters — are not expected to announce any specific targets to cut carbon emissions.

With files from the Associated Press