Joint Chiefs of Staff chairman General Richard Myers' comments came amid an increase in insurgent attacks, some involving multiple car bombings as well as larger, coordinated assaults on military objectives.

"I'm going to say this: I think we are winning, okay? I think we're definitely winning. I think we've been winning for some time," Myers told reporters.

Myers said the number of attacks has recently increased slightly but maintained that it was a poor measure of the insurgency. He noted that half the attacks are thwarted.

But he acknowedged that insurgents were carrying out attacks to the same level as a year ago, and said they could reach higher levels of violence than before the January 30 elections.

"I think their capacity stays about the same. And where they are right now is where they were almost a year ago," he said.

"The essential point is that for things to work in Iraq, you've got to work against what we said, all these lines of operation, of which good governance is one," he said.

Iraq's new leaders have taken nearly three months to form a government, raising US fears that political momentum gained from the elections is being squandered.

US Defense Secretary Donald Rumsfeld emphasized the need for progress toward political and economic stability as key to defeating the insurgency.

"The United States and the coalition forces, in my personal view, will not be the thing that will defeat the insurgency," he said.

"So therefore winning or losing is not the issue, in my view, in the traditional, conventional context of using the word 'winning' and 'losing' in a war," he said.

"The people that are going to defeat that insurgency are going to be the Iraqis. And the Iraqis will do it not through military means solely, but by progress on the political side and giving the Iraqi people a sense that they have a stake in that country," he said.

Rumsfeld reiterated warnings that efforts to develop Iraqi security forces could be set back if Iraq's new leaders make personnel changes based not on competence but on political considerations.

"We can't afford slippage. We need to see that there's some stability," he said.

Rumsfeld and Myers both pointed to an increase in intelligence from Iraqis as a sign of headway against the insurgents.

Myers confirmed reports that US forces narrowly missed capturing Abu Musab al-Zarqawi, the Jordanian militant behind many attacks, in an operation on February 20 near Ramadi.

"We were close," said Myers, who declined to comment on other details of the operation, including the reported capture of a laptop computer belonging to the Jordanian that contained a trove of information.

Asked about Zarqawi's role in the insurgency, Rumsfeld said: "In terms of lethality, I would rank him quite high."

"He may be doing it through proxies, through criminals on some cases. But there have been quite a few suicide attacks in Iraq, and that is not something that criminals tend to get up in the morning and say, 'Gee, I think I'll go engage in a suicide attack.'"

Rumsfeld speculated Zarqawi was being financed and getting recruits from outside the country.

"And they undoubtedly come through Syria and they come through Iran, probably, and through other countries to be available for tasks that he has in mind. And money comes in as well," he said.

He said there was "no question" Zarqawi was connected to al-Qaeda leader Osama bin Laden, who was probably not providing detailed instructions but broad direction.

Connecting the two, he said, were "maybe people, maybe money, maybe communications, maybe an oath of allegiance. Who knows?"