The South Korean government on Friday imposed financial sanctions on three Taiwanese individuals and three Taiwanese entities and a Syrian organization for “indirectly rendering assistance” to the North through weapons trade, the foreign ministry said in a statement.

Any South Korean national found trading with these sanctioned individuals and organizations could face up to three years in prison and 300 million won (approximately $270,000) in fines, according to South Korea's Yonhap News Agency.

“It's evident that they are involved in weapons trade with North Korea. They have already faced U.S. sanctions,” a South Korean ministry official, who spoke on the condition of anonymity, told Yonhap. “We have shared related information sufficiently with the ally and international organizations.”

The sanctioned individuals include Taiwanese businessman Hsien Tai Tsai, who was sentenced to 2 years in prison by a U.S. court in March after he pleaded guilty of engaging in supply of weapons-manufacturing machinery to North Korea. Syria’s state-owned Scientific Studies and Research Center, which is believed to be involved in conducting research and development of nuclear, biological, chemical and missile-related technology, was also blacklisted.

In the past, similar sanctions have been imposed by the South Korean government on 32 other individuals and organizations that are also subjected to U.N. Security Council sanctions over arms trade with the North.

The move comes at a time when ties between the two nations -- which are technically still in a state of war -- show no signs of improving. On Thursday, North Korean officials warned that they had “reached a point of no return” in their relationship with the South following the opening of a U.N. human rights office in Seoul. The office is tasked with monitoring alleged human rights violations across the border in the North.