South Korea's military says North Korea has fired at least one unidentified projectile into the sea in its sixth weapons launch this month. South Korea's Joint Chiefs of Staff on Thursday did not immediately say whether the projectile was a ballistic missile or how far it flew. North Korea has upped its testing activity recently in an apparent effort to pressure the Biden administration in the US amid long-stalled nuclear talks.

The renewed pressure comes as the pandemic further shakes North Korea's economy, which was already battered by crippling US-led sanctions over its nuclear weapons programme and decades of mismanagement by its own government. North Korea issued a veiled threat last week to resume the testing of nuclear explosives and long-range missiles targeting the American homeland, which leader Kim Jong Un suspended in 2018 while initiating diplomacy with the United States.

Kim's high-stakes summitry with former US president Donald Trump derailed in 2019 due to disagreements over sanctions relief and denuclearisation. Some experts say North Korea could dramatically escalate weapons demonstrations after the Winter Olympics, which begin February 4 in China, North Korea's main ally and economic lifeline. They say Pyongyang's leadership likely feels it could use a dramatic provocation to move the needle with the Biden administration, which has offered open-ended talks but showed no willingness to ease sanctions unless Kim takes real steps to abandon the nuclear weapons and missiles he sees as his strongest guarantee of survival.