North Korea vowed to launch three new spy satellites, build military drones, and boost its nuclear arsenal in 2024 as leader Kim Jong Un said US policy is making war inevitable.
The actor had said he was tricked into taking drugs by a bar hostess trying to blackmail him.
Korea has been coming into its own in recent years as an international entertainment powerhouse.
"The US side reiterated that any nuclear attack by the DPRK against the ROK will be met with a swift, overwhelming, and decisive response," a joint US-South Korean statement said on Saturday.
The legacy of Japan's 1910-45 colonial rule of the Korean peninsula remains politically sensitive for both sides.
The Gaza war has revealed the extent to which North Korean rockets are being launched into Israel.
South Korea's military said on Monday it was on alert after North Korea designated Nov. 18 as "missile industry day" to mark its launch of an intercontinental ballistic missile last year.