The statement appears to be a threat to influence / interfere in the US vote.

As recently as April 15, the U.S. Depts of State, Treasury, Homeland Security, and the Federal Bureau of Investigation have issued warnings about the DPRK's malicious cyber activities and ability to disrupt U.S. critical infrastructure.

DPRK state-sponsored cyber actors primarily consist of hackers, cryptologists, and software developers who conduct espionage, cyber-enabled theft targeting financial institutions and digital currency exchanges, and politically-motivated operations against foreign media companies. They develop and deploy a wide range of malware tools around the world to enable these activities and have grown increasingly sophisticated.

An excellent example of their ability to disrupt operations is the deployment of the 2017 WannaCry 2.0 ransomware which infected hundreds of thousands of computers in government offices, hospitals, schools, businesses, and homes in over 150 countries.

In December 2019, Japan's national intelligence agency issued a warning regarding potential North Korea interference in the 2020 U.S. presidential election.

In January 2020, Shelby Pierson, who serves as the intelligence community's election threats executive within the Office of the Director of National Intelligence, stated the following:

"Russia, China, Iran, North Korea, [and] non-state hacktivists all have opportunity, means, and potentially motive to come after the United States in the 2020 election to accomplish their goals."