The Biden administration has indicated that North Korea may be preparing for a nuclear test as US President Joe Biden travels to Asia later this month, White House spokeswoman Jane Psaki said on Thursday. Biden is expected to visit South Korea and Japan from May 20-24 and talk with his South Korean and Japanese counterparts. Psaki said North Korea could conduct a missile test as early as this month. Psaki said Biden is also considering a visit to North Korea’s demilitarized zone (DMZ) but has not decided.

Before becoming president, several former US presidents and Biden himself visited the DMZ. Still, former President Donald Trump became the first to meet there when he met North Korean leader Kim Jong Un for the third time in June 2019. His efforts to persuade him to abandon the nuclear and missile programmes were unsuccessful.

Often described as the world’s last Cold War front, the DMZ has existed since the 1950-53 Korean War ended in an armistice rather than a peace treaty. North Korea has not tested a nuclear bomb since 2017 but resumed ICBM testing this year. “We have shared this information with allies and partners and coordinated closely with them,” Psaki said.

North Korea has recently stepped-up weapons testing, resuming the launch of intercontinental ballistic missiles (ICBMs) for the first time since 2017. For weeks, US and South Korean officials have said signs of new construction in Punggye-RI, North Korea’s only known nuclear test site, and that Pyongyang may soon test another bomb.

On Thursday, North Korea fired three ballistic missiles in waters off its east coast, and South Korea and Japan said in the latest tests aimed at advancing their weapons programmes even though they first reported the COVID-19 outbreak. In condemning the latest launch, the US State Department said it remained committed to diplomacy with North Korea and reiterated its call for Pyongyang to resume dialogue.