The First Deputy Foreign Minister of South Korea , Cho Hyun-dong, Japanese Deputy Foreign Minister Takeo Mori and US Deputy Secretary of State Wendy Sherman pose for photographers ahead of their trilateral meeting at Iikura Guesthouse in Tokyo, Japan, October .| Photograph: The United States, Japan and South Korea warned on Wednesday (10) that a North Korean nuclear test would provoke an "unprecedented response", also promising to show unity after several launches missiles by the communist regime in Pyongyang."We agreed to further strengthen cooperation (...) so that North Korea immediately ends its illegal activities and resumes denuclearization talks," said South Korean Cho Hyun-dong. "The three countries agreed on the need for an unprecedented force response if North Korea conducts its seventh nuclear test," Hyun-dong told a news conference. Seoul and Washington have repeatedly warned that Pyongyang could be about to conduct another nuclear test since 2017. The countries reinforced talks after a series of ballistic missile launches in recent weeks.