South Korea ? South Korea made its first concrete move Thursday to enforce U.N. sanctions imposed on North Korea for its nuclear test, saying it will ban officials from the communist country who fall under a U.N. travel restriction and control financial transactions between the rivals.

Meanwhile, a South Korean Defense Ministry report underscored the lingering threat posed by the North, saying the regime is believed to have enough plutonium to make as many as seven nuclear bombs. The North also is working to make a small, lightweight nuclear warhead that can be carried by ballistic missile, according to the report released by an opposition lawmaker.

Seoul had been hesitant to take strong measures to support the sanctions, mindful of North Korea’s massive armed forces poised at the border, its family and cultural ties, and its wish to expand economic relations with its neighbor.