"Our nation must succeed in Iraq," ambassador Zalmay Khalilzad told a news conference in Baghdad, three weeks ahead of mid-term legislative elections in the United States.
"Despite the difficult challenge we face, success in Iraq is possible," Khalilzad said, predicting "significant progress" on the political front in the coming 12 months. "Our goals for Iraq have not changed."
The military commander in Iraq, General George Casey, said the country's own armed forces should be able to take over security responsibility within the next 12 to 18 months.
"I believe in 12 to 18 months Iraqi security will be completely capable of taking over their own security," Casey told the news conference.
The American general said the Iraqi armed forces had suffered 300 "martyrs" in clashes with insurgents during the holy month of Ramazan that ended this week.
Since the killing of Al Qaeda in Iraq leader Abu Musab al-Zarqawi in a US air strike in June, the insurgents "remain wounded but lethal", he said, while claiming the Americans were winning the battle.
"We have continuously adapted to stay ahead of the enemy," he said.
Casey renewed charges that Damascus and Tehran were meddling in Iraq. "Both Iran and Syria continue to be decidedly unhelpful by continuing to provide support" to the insurgents, he said.

Copyright AFP (Agence France-Presse), 2006