South Korea, the United States and Japan are preparing to announce their own sanctions on North Korea at the same time in a joint action to maximize their impact to the communist country, Foreign Minister Yun Byung-se said Thursday.

"Basically, (the three countries' independent sanctions) will be announced concurrently or at a very similar time," Yun told Yonhap News Agency, referring to the nations' follow-up measures to the United Nations Security Council's adoption of Resolution 2321.

The resolution slapped on a new package of sanctions, mainly targeting the North's lucrative coal exports, in response to its fifth and biggest nuclear test on Sept. 9. 

"It's hard to pinpoint the exact timing (of the announcement) since each country should follow internal procedures, but the focus is on driving (the sanctions) in a way that amplifies the effects," Yun noted.

Bilateral sanctions prepared by the US side may be strong enough to hurt North Korea more than the recent UNSC resolution, he also noted.

The foreign minister hailed the latest UN action as "the most powerful and comprehensive sanctions in the history of sanctions on North Korea."

The resolution newly mentioned the possibility of suspending the rights and privileges of UN member states, a new element in the push to isolate North Korea diplomatically, he assessed.

South Korea's foreign ministry spokesman Cho June-hyuck said earlier this week the government plans to unveil its own sanctions on the North at the earliest time possible following the UNSC resolution.  (Yonhap)