Homeland Security Director Tom Ridge told newspaper executives Monday that the color-coded alert system used to keep the nation apprised of the danger of terrorist threats may have to be "tweaked" in the days to come.

"There has been some criticism," Ridge said during the luncheon session of The Associated Press annual meeting. "Frankly, we had a 45-day comment period; we got a lot of good input ... We may end up tweaking it, based on recommendations that we've received from a lot of people around the country."

He did not specify what changes might be made but acknowledged the need for "a national vocabulary with standards that everybody can accept."

Later, Ridge spokesman Gordon Johndroe said the public comments will be studied during a 90-day review period. "It's too early to say whether there will be any more refinements," he said.

Under the five-level alert system announced last month, the risks can range from green (low) to red (severe), with blue, yellow and orange layers in between. At present, the whole nation is under a midlevel yellow alert — for "significant risk of terrorist attacks."

In a question-and-answer session with publishers, Ridge was asked whether authorities have been too quick to issue warnings about possible attacks on shopping centers or Northeastern banks and whether the public might grow complacent in the face of such warnings when the threats go unrealized.

Given the constant flow of bits and pieces of information that authorities must deal with daily, the decision on when to share or not share that information is difficult, Ridge said.

"There will never by a mathematical certainty as to the kinds of information we share," he said.

In his speech, Ridge reviewed for the first time plans to release this summer or fall a national strategy to rank the nation's homeland defense needs. He called it a strategy of "risk management" that will focus government resources where the risks are the highest, where most lives can be saved and most property can be protected.

Bioterrorism, for example, poses one of the greatest threats for massive loss of life "and our preparedness has historically lagged behind the threat," Ridge said.

Ridge said his office is working with states and the private sector to study the nation's infrastructure and determine where the greatest risks are.

He told the news executives that the homeland defense strategy "will answer two questions often asked by your reporters, and rightly so: `Whose job is it — and who pays for it?"'

Ridge said the fear of terrorism has dimmed for many Americans since Sept. 11.

"The world is just as dangerous today, if not more so," he said. "The threat is real; it's as real as it was seven months ago. In fact, it is a permanent condition to which this country must permanently adapt."

Later, Ridge was asked about the threat of terrorists getting their hands on nuclear weapons or exploding nuclear materials in a "dirty bomb." He replied that there is evidence the Al Qaeda are seeking nuclear technology.

"If they obtain it one way or another I don't have any doubt they will try to use it," he said.

U.S. officials have said they have no indication that Al Qaeda terrorists have obtained material for such a bomb.

Following the terrorist attacks, President Bush named the former Pennsylvania governor to be the White House point man for domestic defense programs. The assignment touches on scores of federal activities, including border control, intelligence and safeguards against bioterrorism strikes.

Some in Congress want to give the position Cabinet-level status, which would grant lawmakers oversight power and, they say, increase Ridge's influence. Bush has balked, insisting that he has given Ridge enough power to overhaul homeland security from his working space just a few steps from the Oval Office.