South Korea says it will sanction 40 individuals and 30 organizations aboard, mostly in North Korea, as part of its unilateral punitive measures the North for its recent nuclear test and rocket launch.

Tuesday's announcement came a day after North Korea warned of pre-emptive nuclear strikes in response to the start of annual South Korean-U.S. military drills. Pyongyang views the drills as an invasion rehearsal.

The South Korean government also said in a statement that it will ban the entrance of any ship which has also stopped at a North Korean port in the previous 180 days. Currently only North Korean ships are banned.

It says the sanctions target 38 individuals and 24 organizations in North Korea, and two individuals and six organizations in third countries.

It says South Koreans will be barred from engaging in financial dealings with those blacklisted people and organizations.