Russian President Vladimir Putin is again raising the possibility of such an attack. Experts said the likelihood still remains low, though risks are rising.
North Korean leader Kim Jong Un said his country will never abandon the nuclear weapons it needs to counter the United States, which he accused of pushing to weaken the North's defenses.
Russian President Vladimir Putin gave orders to his nation's nuclear forces over the weekend, but their exact meaning is unclear. Russia has more nuclear weapons than any other nation.
As North Korea's dictator marks a milestone on Friday, he might be facing his toughest moment yet, as crushing sanctions, the pandemic and growing economic trouble converge
Citing President Biden's speech to Congress, North Korea says the United States will face a grave situation if it continues to pursue its "hostile policy" toward the country's nuclear program.
Kim's comments come just days ahead of President-elect Joe Biden's inauguration. Biden has promised "principled diplomacy" with North Korea, implying a break with Trump's high-stakes summits.
In the midst of a pandemic that's wreaking havoc on prisons and disproportionately affects older people, activists known as the Kings Bay Plowshares have been sentenced to up to 33 months in prison.
The bombings of Hiroshima and Nagasaki were said at the time to be justified as the only way to end World War II. Seventy-five years later, legal experts say they would now be war crimes.