SEOUL, Feb. 20 (Yonhap) -- South Korea said Monday it has decided to impose additional independent sanctions on North Korea in response to its latest long-range ballistic missile launch and the firing of two short-range ballistic missiles.

The government is imposing the sanctions on four individuals and five institutions involved in the secretive regime's nuclear and missile development programs or helping Pyongyang evade sanctions, according to the foreign ministry.

Those blacklisted include Ri Song-un, former economic and commercial counselor at the North Korean Embassy in Mongolia, and Vladlen Amtchentsev, a Russian-born South African national who has helped North Korea buy oil illegally, it said. Ri is known to have negotiated trade deals involving weapons and luxury goods,

Among the organizations facing Seoul's measure are Songwon Shipping & Management, Korea Daizin Trading Corp. and Transatlantic Partners Pte. Ltd., all of which have already been sanctioned by Washington

Previously, the Yoon Suk Yeol administration imposed sanctions on the North on Feb. 10 over crypto theft and cyberattacks.

The top nuclear envoys of South Korea, the United States and Japan, meanwhile, denounced North Korea's latest provocations via phone consultations.

Kim Gunn, Seoul's special representative for Korean Peninsula peace and security affairs, held back-to-back talks with his U.S. and Japanese counterparts -- Sung Kim and Takehiro Funakoshi, respectively -- over the phone and warned that the North will clearly face "consequences" for its provocations, according to the ministry.

The envoys agreed to further strengthen cooperation with the international community for the thorough implementation of the U.N. Security Council resolutions against the North, the ministry added.