North Korea has threatened to sink Japan and reduce the US to "ashes and darkness" for leading the latest UN Security Council sanctions imposed on the country.
The Security Council on Monday unanimously approved a US-drafted resolution, which bans Kim Jong-un's government from exporting textiles and restricts the shipment of oil products.
Reacting to the vote on Thursday, North Korea said the US ought to "be beaten to death" for spearheading the penalties.
The Korea Asia-Pacific Peace Committee, which handles Pyongyang's external ties and propaganda, also singled out Tokyo for "dancing to the tune" of the US-led resolution.
"The four islands of the archipelago should be sunken into the sea by the nuclear bomb. Japan is no longer needed to exist near us," a statement carried by North Korea's state media organisation, the Korean Central News Agency (KNCA), said.
Japanese officials strongly condemned the statement, labelling it "extremely provocative and egregious".
"It is something that markedly heightens regional tension and is absolutely unacceptable," Yoshihide Suga, Japan's chief cabinet secretary, said on Thursday.
Tensions have risen in the area in recent weeks following North Korea's sixth, and most powerful, nuclear test to date on September 3.
The sanctions, which also make it illegal for foreign firms to form commercial agreements with North Korean organisations, were approved by all 15 members of the Security Council, including China and Russia.
Nikki Haley, the US ambassador to the UN, claimed the measures - which are a watered-down version of the original US-drafted plan - will starve North Korea of at least $1.3bn in annual revenues.
She told the Security Council on Monday that the US continues to seek a peaceful resolution to the crisis, saying North Korea has not yet "passed the point of no return".
"If it [North Korea] agrees to stop its nuclear programme, it can reclaim its future. If it proves it can live in peace, the world will live in peace with it," she said.
Source: News agencies