SEOUL, South Korea — North Korea said Wednesday that it saw no reason to negotiate with the “gangster-like” United States any more, warning that it was ready to fight any type of war with Americans, including ones involving cyberattacks and nuclear weapons.

In a statement carried by the official Korean Central News Agency, the North’s National Defense Commission said Wednesday that now that the United States intended to “bring down” the North’s government and unleash a “war of aggression,” it, too, was ready to fight with “miniaturized, precision and diversified nuclear-striking means,” as well as “cyberwarfare means,” to “write the last page” of American history.

In an interview carried on YouTube on Jan. 22, President Obama predicted that a state like North Korea would “collapse” over time, saying that the Internet would inevitably penetrate North Korea, isolated as it was, with its democratic influences.