Australia's prime minister declined Saturday to commit to a timeline for withdrawing his country's forces from Iraq, but insisted that steady progress was being made.

John Howard spoke to reporters in Baghdad, where he arrived after his plane made an emergency landing in southeastern Iraq because it had filled with smoke after takeoff from an airbase there, according to the Australian Associated Press.

Howard, a staunch U.S. ally who was making his first trip to Iraq, has been under increasing political pressure to set an exit strategy for Australia's 1,400 troops from Iraq. Opinion polls show the Iraq conflict is deeply unpopular among Australians.

"Great progress has been achieved, but there is still work to be done," Howard said during a news conference with Iraqi Prime Minister Nouri al-Maliki. "As you know, I don't set speculative dates. There is nothing to be achieved by that."

Al-Maliki said Australian help has been successful in helping to fight the Sunni insurgency in southern Baghdad, but stressed the dangers in calling the mission a success prematurely.

"The mission is still ongoing. We have a desire for Australia to remain and to continue its support until we are completely confident that all terrorist activities cease," al-Maliki said.

The C-130 Hercules, which was carrying Howard and 30 other people, including media and military personnel, filled with smoke soon after takeoff en route to Baghdad and turned around after reaching an altitude of about 5,000 feet, according to AAP.

No injuries were reported and Howard continued his trip to Baghdad on a second aircraft, the news agency said.