Lee, speaking at an Asian security meeting in Singapore, said the situation on the Korean peninsula posed a global threat and he urged North Korea to immediately end its nuclear weapon and missile programmes.

The US warned this month that North Korea is preparing to conduct a seventh nuclear test, and says it will again push for UN sanctions if that happens.

“Our government will strengthen capabilities to better implement the US extended deterrents and will dramatically enhance response capabilities,” Lee said in a speech at the Shangri-La Dialogue, a top regional security summit.

“Moreover, we seek to strengthen ROK (Republic of Korea), US, Japan trilateral security cooperation to respond to North Korea’s nuclear and missile threats.”

North Korea promoted its key nuclear negotiator to foreign minister, state media said on Saturday, as leader Kim Jong-un vowed to his ruling party that he would use “power for power” to fight threats to the country’s sovereignty.

North Korea has carried out at least 18 rounds of weapons tests this year, underscoring its evolving nuclear and missile arsenals.