The U.S. says the details of additional sanctions on North Korea will be announced within the next two weeks.

In a daily briefing, State Department spokesman Philip Crowley said that new efforts with key governments will be made to keep North Korean trading companies engaged in illicit activities from operating in those countries and that banks will be prevented from facilitating these companies' illicit transactions.

Crowley said that U.S. coordinator of North Korea sanctions Robert Einhorn will visit South Korea and other international partners early next month to discuss the sanctions.

Crowley added that foreign banks engaging in illicit transactions with North Korea will be restricted from operating in the U.S.

He said that Washington will attempt to interrupt the North's counterfeiting operations, its smuggling of tobacco and liquor and its weapons exports to the Middle East.

Secretary of State Hillary Clinton will ask for China's cooperation on the sanctions when she meets with Chinese Foreign Minister Yang Jiechi at the ASEAN Regional Forum in Vietnam on Thursday.

North Korea is expected to lash out at the U.S. sanctions, which could lead to a protracted confrontation between the two sides.