Washington ? Homeland Security Director Tom Ridge will soon make public a new terrorism alert system to grade threats by their seriousness and give states and cities more specific information.

The new system is said to have several alert levels, with the highest meaning an attack is considered imminent.

The system is described as a response to complaints that the four broad terror alerts issued by the federal government in the months since the Sept. 11 attacks alarmed the public while providing little or no useful information.

The White House confirmed published reports that Ridge and his staff are working with federal, state and local officials, police chiefs and sheriffs with the aim of making the alerts more useful.

“I may be the director of homeland security, but I can’t tell the states and the local communities and the private sector that they have to use the system,” Ridge told Fox News Channel last week. “So we’re going to lay it out there, and say that this is what the federal agencies and the federal government are going to do.”

“We want comments back from everybody  then we’ll review it,” Ridge said.

He said he expects to announce the plan by the end of the week. “Hopefully the states and the local communities will buy into it.”

If it works properly, Ridge said, the result will be that if the federal government raises the status of an alert a notch, “then you have to raise your preparedness, your response mechanism a notch.”

“It’s important that everybody buy into it and accept it,” Ridge said.