North Korea leader Kim Jong Un said his country's hard-won nuclear weapons were a solid security guarantee and a "reliable, effective" deterrent that could prevent a second Korean War.
A report suggested North Korean troops were taking down loudspeakers recently reinstalled at the fortified border.
Kim Yo Jong appears to be stepping out without her elder brother Kim Jong Un. Analysts say that may indicate that she could be moving into a bigger role within the country's leadership structure.
North Korea made good on its threat to demolish the inter-Korean liaison office on Tuesday. South Korea confirmed that the building was demolished by "bombing."
"The U.S. professes to be an advocate for improved relations with the DPRK, but in fact, it is hell-bent on only exacerbating the situation," North Korean foreign minister Ri Son Gwon said.
"It would be good not only for the U.S. interests but also for the easy holding of upcoming presidential election," Kwon Jong Gun, director-general for U.S. affairs at North Korea's Foreign Ministry, said.
The North's Korean Central News Agency said all cross-border communication lines will be cut off in "the first step of the determination to completely shut down all contact means with South Korea and get rid of unnecessary things."
Kim Yo Jong, sister of North Korea's leader Kim Jong Un, warned of the possible scrapping of the inter-Korean military agreement that promised to eliminate practical threats of war as a result of the clandestine leafletting.
North Korean leader Kim's absence from public ceremonies on the birth anniversary of his grandfather and founder of the country, Kim Il Sung, was unprecedented, and he has not been seen in public since -leading to days of speculation over his health.
European markets closed sharply lower on Tuesday as oil market volatility and the coronavirus outbreak remained in focus.
The Korean won weakened on Tuesday against the dollar on unconfirmed reports that North Korean leader Kim Jong Un is seriously ill.
North Korea marked the anniversary of the birthday of its founding father and Kim's grandfather, Kim Il Sung, as a national holiday on April 15, but Kim was not seen in attendance.
In the afternoon of Asian trading hours on Tuesday, the price of the May WTI contract shed earlier gains to fall back into negative territory.
Manufacturing in China shrank at the fastest pace ever recorded in February, stung by the coronavirus outbreak.
South Korean President Moon Jae-in says U.S. President Donald Trump's recent letter to North Korea's leader underscores his commitment to negotiations.
The United States is said to have reached out to North Korea to restart diplomatic talks that stalled last October, news website Axios reported.
North Korean leader Kim Jong Un is set to make a New Year address on Wednesday which is likely to offer a glimpse of a "new path" he has vowed to take if the U.S. fails to meet his deadline to soften its stance over denuclearization.
Scott Seaman, Asia director at Eurasia Group, says "the big question" is whether Pyongyang will test an intercontinental ballistic missile.
North Korean leader Kim Jong Un convened a weekend meeting of top Workers' Party officials to discuss policy matters.
Since 2011, Kim Jong Un has launched more missiles than his father and grandfather combined.
Data also provided by 
