The good news for U.S. media is that publications accounted for 100 percent of U.S. exports.

The figures showed the United States exported $3,000 worth of books, newspapers and other publications to the North in 2006, while there were no shipments from the communist state.

Last year's trade volume marked the lowest point since 1990 when the U.S. began keeping track, Seoul's Yonhap News Agency reported, citing a report from the Commerce Department.

U.S. exports to the North in previous years were mostly books, cereals, vegetables and vegetable oil, dairy products and miscellaneous textile articles.

There were no U.S. imports from North Korea, except in 2004 and 2005 when the United States bought $1.4 million worth of organic chemicals and $77,000 worth of woven apparel, respectively.

The United States imposed a sweeping trade embargo on Pyongyang in June 1950 when North Korea started the Korean War.

Following the imposition of sanctions, North Korea's trade with Japan, once its second-largest partner, also dipped, accounting for only 4.1 percent of its entire trade volume last year.

The U.S.-led trade sanctions have deepened the North's reliance on China, its only remaining communist ally. The North's trade with China accounted for 56.7 percent of is entire trade volume last year, up from 52.6 percent in 2005 and 48.5 percent in 2004.

North Korea's trade volume reached $2.99 billion last year, down 0.2 percent from the previous year. North Korean exports fell 5.2 percent from a year earlier to $947 million, while imports rose 2.3 percent to $2.04 billion.