WASHINGTON (CNN) -- U.S. government officials have recommended to President Bush that the national threat level be raised from elevated risk of terrorist attacks to high risk, sources said Friday.
It is not known when the president might decide the issue. The national threat levels, developed after the September 11 attacks, are part of a color-coded system. Currently the level stands at elevated risk -- or yellow. High risk would be orange.
The recommendation follows several days of debate within the government about whether to take such an action.
Counterterrorism officials have said they are more worried about a possible terrorist attack due to several factors, including an increase in the so-called "chatter" level.
The stepped-up chatter indicates a greater amount of intelligence coming in about a possible attack, especially by al Qaeda, the culmination beginning this weekend of the Hajj pilgrimage to Mecca, Saudi Arabia, and the continuing confrontation with Iraq, according to officials.
Also worrisome to U.S. officials is increased intelligence from a variety of sources in recent weeks suggesting a possible future attack in the United States that could include chemical or biological weapons.
The information does not single out any specific chemical agent or target, but officials said they are mostly concerned about the vulnerability of so-called "soft targets," such as apartment buildings, sports arenas and amusement parks.
Since the inception of the color-coded threat level system -- officially called the Homeland Security Advisory System -- in March 2002, the status has been yellow the whole time except for a short period around July Fourth when it was raised to orange.
Deputy White House Press Secretary Scott McClellan said the threat level remains at yellow, but it is being reviewed as intelligence comes in to officials.