Activity around two test tunnels at North Korea's nuclear detonation grounds suggests the nation could be preparing to carry out its second underground atomic blast this year, Kyodo News reported.
The Punggye-ri test site is "showing activity " close to its second and third underground detonation chambers, anonymous sources informed the South Korean JoongAng Ilbo newspaper. Multiple vehicles have been spotted transporting dirt to the tunnels. The site's second tunnel is understood to have been used for last week's nuclear test.
South Korean intelligence officials have detected considerable movement at the third tunnel including traffic involving high-end cars and shuttle vehicles. "These movements are similar with those seen in the final stages of preparing for the third nuclear test," an anonymous South Korean official told the newspaper.
A North Korean envoy this week warned of a "second and third steps" to come following last week's nuclear blast if the United States pursues an antagonistic policy toward Pyongyang, according to Reuters.
In threatening the South with "final destruction," North Korean diplomat Jon Yong Ryong told a meeting of the international Conference on Disarmament that, "As the saying goes, a new-born puppy knows no fear of a tiger."
The United States and other member nations to the Geneva, Switzerland-based forum criticized the rhetoric. The threat was"completely inappropriate," said British envoy Joanne Adamson.
The Chinese Foreign Ministry on Monday rebutted a Reuters report that it received notification from Pyongyang of plans to carry out new atomic tests and rocket firings, according to a Global Times report.
U.S. State Department spokeswoman Victoria Nuland on Friday urged the North to abstain from "additional provocative actions" that could include another nuclear blast, Reuters reported.
The European Union on Monday approved a range of new economic penalties against North Korea as punishment for last week's atomic test, Agence France-Presse reported.
The new sanctions include the restraining assets held abroad by certain targeted persons as well as prohibitions on select individuals' ability to move freely in EU nations, according to the European bloc.
The U.S. House of Representatives on Friday nearly unanimously approved a resolution that urges the Obama administration to press for new international sanctions targeting Pyongyang. The measure also called on Beijing to press the North to end its nuclear arms and missile development and to take steps to keep such technology from being shipped through Chinese territory, according to the Associated Press.
The U.N. Security Council is also eyeing new sanctions against the North. A senior Russian official said Moscow does not want to see additional economic punishment placed on Pyongyang, Reuters reported.
"Any additional measures of pressure on North Korea should be aimed exclusively at the sphere of non-proliferation of nuclear arms and rocket launches," said Deputy Foreign Minister Gennady Gatilov. "We are against measures that would affect normal trade and economic relations with North Korea. We understand our Chinese colleagues have similar views."
Even while under heightened Security Council sanctions for years, North Korea has been able to further its nuclear weapons and ballistic missile development by devising sophisticated money-making cons and figuring out ways for smuggling currency obtained abroad past foreign officials, Reuters reported.
The Stalinist regime also supports itself by printing fake currency and selling drugs and weapons on the black market, according to the United States.
Meanwhile, the Preparatory Commission for the Comprehensive Test Ban Treaty Organization on Saturday revised downward from 5.0 to 4.9 on the Richter scale its assessment of the size of last week's seismic shock waves created by North Korea's nuclear blast, Yonhap reported.
CORRECTION: An earlier version of this article cited reporting in Nature that scientists in Japan and Russia had identified xenon 133 seemingly released by the North Korean nuclear test. Nature subsequently removed its Feb. 19 article after being alerted to problems with the analysis.