The South Korean military says it has staged joint maritime exercises with Japan and the United States, with the participation of a US nuclear-powered aircraft carrier.

South Korea's Joint Chiefs of Staff said on Wednesday that the drills were aimed at bolstering deterrence and response capabilities against North Korea's nuclear and missile threat.

South Korean military officials said the exercises were held from Monday to Wednesday in waters south of the country's southern island of Jeju.

They said nine ships took part in the drills including the USS Carl Vinson, the Japanese Maritime Self-Defense Force and South Korean navy vessels.

They said the chairman of the joint chiefs of staff, Admiral Kim Myung-soo, came to encourage the sailors on the aircraft carrier on the first day.

South Korea, Japan and the United States, conduct joint military exercises regularly. The latest drills are the first under a multi-year plan agreed in December.

The South Korean government said on Wednesday that it has imposed fresh sanctions on parties involved in illicit ship-to-ship transfers of goods for North Korea.

The South Korean foreign ministry said the 11 ships, two individuals and three organizations have been carrying out the transfers in violation of UN sanctions.

This is the15th time that the administration of South Korean President Yoon Suk-yeol has announced sanctions on North Korea.