The Bush administration has defended its partial release of a report linking the Iraq conflict to global terrorism against calls for the full report.
A White House aide said the terror report could not be released in full because of national security issues.
Opposition Democrats argue that the parts of the intelligence report declassified on Tuesday do not give Americans enough information.
There are also rumours of a damning second report being held back.
Jane Harman, the top Democrat on the House Intelligence Committee, suggested this alleged second report, focusing only on Iraq, was being "held until after the November [mid-term] elections".
She had not seen the alleged report, but added: "I hear it paints a grim picture."
'Information for al-Qaeda'
President George W Bush released excerpts from the National Intelligence Estimate (NIE) on global terror - compiled by all 16 US intelligence agencies - after leaks to the US media.
The leaked excerpts from the report were first published by the New York Times on Sunday.
White House homeland security adviser Fran Townsend said parts of the NIE had been held back because they "go directly to national security concerns" and there were concerns about disclosing sources and methods.
Peter Hoekstra, the Republican chairman of the House Intelligence Committee, said the administration was wary "about the kind of information we want to give al-Qaeda".
The decision to release some of the NIE was endorsed by US Defense Secretary Donald Rumsfeld.
"The American people and the world will be able to see the truth and precisely what that document says," he said on a visit to Albania.
Correspondents say the NIE excerpts give some comfort to the White House because they conclude that victory in Iraq would be a big blow to the enemy.
Key points of the report include
- the Iraq conflict has become a rallying cause for jihadists
- Militants, although a small percentage of Muslims, are increasing in both number and geographic dispersion
- If this trend continues, threats to US interests globally will become more diverse leading to increased attacks worldwide
- Militants consider Europe an important venue for attacking Western interests
- The loss of key leaders in rapid succession would probably fracture al-Qaeda into smaller groups that would pose, at least for a time, a less serious threat to US interests
Debate voted down
Mr Bush has accused those behind leaking the terror NIE of trying to mislead the American public for political purposes ahead of the November elections.
Democrat Senators Edward Kennedy, Hillary Clinton and Carl Levin said the public needed to know more from the report and accused the administration of selective declassification.
"The American people deserve the full story, not those parts of it that the Bush administration selects," Sen Kennedy said.
"President Bush should declassify the entire NIE."
They also called for a briefing behind closed doors with John Negroponte, the director of national intelligence.
A Democrat proposal for a secret session of the House of Representatives to give lawmakers the chance to discuss the report was voted down.