"We've got to continue to work to improve our intelligence capabilities, and we've got to continue to confront the threats posed by the regimes of North Korea and Iran," said spokesman Scott McClellan.

"We're pursuing diplomatic approaches to get them to open up to the international community and fulfil their international obligations. That's what we're working to do," McClellan told reporters.

He spoke after a presidential commission said pre-war US intelligence on Iraq's weapons of mass destruction was "dead wrong" and warned that US spy agencies lack information about countries like Iran and North Korea.

"The bad news is that we still know disturbingly little about the weapons programs and even less about the intentions of many of our most dangerous adversaries," the panel said in its 600-page report.

Separately, US President George W. Bush indicated that he still believed in using the preemptive military force against rising threats, a doctrine he articulated after the September 11, 2001 terrorist attacks and applied to Iraq.

"My administration will continue to make intelligence reforms that will allow us to identify threats before they fully emerge so we can take effective action to protect the American people," he told reporters.

"We need to prevent terrorists from getting their hands on the weapons of mass murder they would like to use against our citizens," Bush said as he unveiled the presidential commission's report on flawed intelligence.

Bush, who lumped Iraq with North Korea and Iran in an "axis of evil," ordered the war on Iraq on grounds that Saddam Hussein possessed weapons of mass destruction and could give them to terrorists targeting the United States.

The commission said after a year-long enquiry that the flaws that crippled analysis of Iraq "are still all too common" and warned that US intelligence on countries like Iran and North Korea lacks critical information.