The South Korean government announced additional sanctions against Iran on Friday over its nuclear program, blacklisting 99 Iranian firms and six individuals.

The government also issued an advisory on Korean companies to be cautious in their purchase of Iran’s petrochemical products.

But the Finance Ministry said the new punitive measures will not affect Korea’s imports of crude oil from Iran, which accounts for about 10 percent of domestic needs.

Under the new sanctions, those on the blacklist will be required to get approval from Korea’s central bank for foreign currency transactions. But the ministry did not reveal the names on the list.

In September last year, the government designated 102 groups and 24 individuals as subject to a ban on financial transactions.

Korea’s sanctions are the latest in a drive against Iran’s nuclear program, led by the United States.

The U.S., Britain and Canada imposed sanctions last month against Iran’s financial, petrochemical and energy sectors.

The Korean move follows new U.S. legislation which punishes foreign firms buying Iranian oil through that country’s central bank.

The U.S. has been urging its Asian allies to press Tehran after the International Atomic Agency in November reported that Iran had been advancing efforts to produce enriched uranium, an ingredient used to make atomic weapons.

Last year, Korea joined the European Union and Japan in imposing sanctions against Iran, part of which call for Korean individuals, businesses and other entities to get prior approval from the Bank of Korea when conducting financial transactions with Iranian banks.

Those entities include the Bank Mellat Seoul office, the Iranian Revolutionary Guard Corps and the Islamic Republic of Iran Shipping Lines.

Bank Mellat has asked Korean regulators to take the company off a list of institutions whose transactions must be approved by the central bank. The Korean government at the end of last year allowed Iran’s central bank to open accounts denominated in Korean won to settle payments from oil exports.

By Cynthia J. Kim (cynthiak@heraldcorp.com)