Armored Secret Service bus to hit campaign trail.

The Secret Service has bought two armored buses at a cost of $1.1 million each for use by the president, other government officials and candidates for president, the agency told NBC News on Thursday.

Agency spokesman Ed Donovan said the buses were expected to be delivered next month.

Donovan would not disclose any security features of the buses but confirmed that they are being manufactured by a company in Tennessee. He emphasized that these buses were not exclusively for the president.

Source: Dave Forman for NBC News.