The Treasury Department's Office of Foreign Assets Control ("OFAC") issued guideline for violation penalty. The public comment is due no later than 60 days from issuance.
It basically state, if the violation is self-disclosed, the penalty will be one-half of not being voluntarily disclosed. The statutory maximum will be imposed in case of no self-disclosing. It is, therefore, motivating and urging companies to voluntary disclosure.
In Japan, METI don't issue any guideline of minimizing penalty in case of voluntary disclosure.
However, it is said the willingness of cooperation of disclosure or good attitude will lead to favorable result. (There is no guarantee, though....)
(Source: IRB NO 403: OFAC Issues Economic Sanctions Enforcement Guidelines http://www.bryancave.com/bulletins/ )