Federal officials said they were ready to begin building a new "virtual fence" along the U.S.-Mexico border.

They expected it to cover nearly the entire 2,000-mile boundary within five years.

That construction could start within weeks, the executive director of the Homeland Security Department's Secure Border Initiative program told The Associated Press.

The first towers holding sensors, cameras and communications gear to detect drug smugglers and illegal immigrants will be built along 53 miles of Arizona's border with Mexico. Towers on the remaining 320 miles of the state's southern border will follow.

New Mexico will get virtual fencing next, followed by California and most of Texas, Project director Mark Borkowski said.