WASHINGTON - The US Department of Homeland Security on Wednesday announced the implementation of a new terror alert system to replace the current color-coded one.

The department said in a statement the new system, formally known as National Terrorism Advisory System (NTAS), "provides timely information to the public about credible terrorist threats."

The current terror alert system, which uses five colors to represent different levels of terrorist threat, was created in March 2002 by then President George W. Bush, but was widely criticized as being confusing and too vague.

Under the new system, there will be two levels of threat, "imminent threat," which warns of a credible terrorist threat against the United States, and "elevated threat," which warns of a credible, specific, and impending terrorist threat, according to the department.

NTAS alerts provide a concise summary of the potential threat, including geographic region, and mode of transport or critical infrastructure potentially affected by the threat, said the statement.

The alerts also include actions being taken to ensure public safety, as well as recommended steps that individuals, communities, business and governments can take to help prevent, mitigate or respond to a threat.

"The terrorist threat facing our country has evolved significantly over the past 10 years and, in today's environment, more than ever, we know that the best security strategy is one that counts on the American public as a key partner in securing our country," Homeland Security Secretary Janet Napolitano said when unveiling the new system.

Under the current color-coded system, green, at the bottom, signals a low danger of attack; blue signals a general risk; yellow, a significant risk; orange, a high risk, and red, at the top, warns of a severe threat. The government has kept the national terror alert level at yellow since 2006.