Ri Pyong Chol, vice-chairman of the Central Military Commission of the North's ruling Workers' Party, denounced ongoing joint military exercises by the US and South Korea as openly showing "reckless ambition for aggression."

US and South Korean forces have carried out various training exercises in recent months, including the biggest-ever live-fire exercises last week, after many drills were scaled back amid COVID-19 restrictions and diplomatic efforts with North Korea.

North Korea has said it has completed development of its first military spy satellite, and leader Kim Jong Un has approved final preparations for the launch. The launch would be the North's latest in a series of missile launches and weapons tests, including one of a new, solid-fuel intercontinental ballistic missile last month.