North Korea could conduct a nuclear weapons test next week around the anniversary of founder Kim Il Sung's birth, Washington's top envoy for North Korea said.

"We are worried that, in connection with the upcoming April 15th anniversary, the DPRK may be tempted to take another provocative action," Sung Kim, U.S. special representative to North Korea, said in a briefing call with reporters held Wednesday. "We obviously hope not, but we will be prepared."

The Democratic People's Republic of Korea is the official name of North Korea.

"I don't want to speculate too much, but I think it could be another missile launch, it could be a nuclear test," Kim said.

 

Pyongyang has conducted six nuclear tests since 2006. It's last, in September 2017, was of a weapon estimated to have a yield of 140 to 250 kilowatts -- at least 10 times as powerful as the atomic bomb dropped by the United States on Hiroshima, Japan, in 1945.

North Korean leader Kim Jong-Un declared a moratorium on long-range missiles and nuclear tests ahead of his 2018 summit with then-U.S. President Donald Trump.

However, the secretive regime has conducted a dozen weapons tests since the beginning of this year, including the March 24 firing of an intercontinental ballistic missile, which effectively ended the moratorium.

Observers have detected heightened activity. North Korea's Punggye-ri nuclear test site, suggesting a forthcoming detonation.

The rhetoric emerging from Pyongyang in recent days has also highlighted the regime's nuclear capabilities.

Kim Yo Jong, the influential sister of Kim Jong Un, warned Tuesday. that the North would respond to any military confrontation by South Korea with a nuclear attack causing "destruction and ruin."

Nuclear negotiations between Washington and Pyongyang have stalled since a second Trump-Kim summit, in February 2019, ended without an agreement.

The Biden administration has indicated that it wants to restart discussions with North Korea, but the U.S. envoy said Wednesday that their efforts have gone unanswered.

"We have not received any response from Pyongyang, which is very disappointing because we have sent several messages, both public and private, inviting them to a dialogue without any conditions," Kim said.

Kim added that the United States and its allies in the region are ready for whatever provocations North Korea has in store.

"The important thing is that we, in cooperation and coordination with our allies and partners, are prepared to deal with whatever they may undertake," he said