The United States is reportedly tracing more than 200 overseas bank accounts that North Korea has been allegedly using for illegal financial transactions.

A diplomatic source said Friday that the U.S. Treasury Department and intelligence authorities have discovered around 200 accounts in overseas banks that North Korea is suspected of having used for illegal dealings and for depositing payments it received from exporting weapons in violation of U.N. resolutions.

The source said the U.S. will likely seek to freeze the assets in half of the 200 accounts after notifying the banks of such plans.

The recent move by the Treasury Department comes separately from the U.S. handling of the “Cheonan” naval incident. The department has been tracing such accounts since last year when U.N. Security Council resolution 1874 was adopted.

Meanwhile, in the State Department, spokesman Philip Crowley said that Washington will unveil within two weeks a package of sanctions aimed at blocking various illegal acts by the North that could finance Pyongyang’s proliferation of weapons of mass destruction.