South Korea has imposed its own sanctions against Russia for helping North Korea in ways that may help it build up its military.

South Korea's foreign ministry announced that two Russian ships, two organizations, and two individuals representing these organizations are subject to the sanctions.

The ministry said the ships were involved in moving military supplies between Russia and North Korea in violation of UN Security Council resolutions. The ships are now banned from entering South Korean ports without permission.

The two organizations and their representatives are said to have helped North Korean IT workers enter Russia, such as by providing documents.
They are suspected of helping these workers earn foreign currency for Pyongyang's nuclear and missile programs. Under the sanctions, the companies and individuals face limitations on monetary transactions in South Korea.

Seoul demands that Russia immediately stop any unlawful relations with the North, including military cooperation. The foreign ministry said such cooperation seriously threatens peace and stability beyond the Korean Peninsula and around the world.

It also said Seoul will consider additional sanctions if necessary, citing a possible threat to national security.

The sanctions come as Moscow appears to be trying to strengthen ties with North Korea. Russia's foreign intelligence agency chief visited Pyongyang in March. The Russian side has also indicated that President Vladimir Putin may pay a visit.