THE North Korean leader, Kim Jong-un, vowed to defend his country against hostility from the United States after the totalitarian state said last week it would test a nuclear weapon.
Mr Kim supported government statements that ''powerful physical countermeasures would be taken to defend'' the dignity and sovereignty of the nation, the official Korean Central News Agency reported on Saturday.
North Korea has probably made enough progress to test a weapon in ''a few weeks or less'' once the leadership gives the order, according to a statement on the 38north.org website of the US-Korea Institute at Johns Hopkins School of Advanced International Studies, where satellite photos were analysed.
North Korea on January 24 threatened to test nuclear weapons to derail ''hostile'' US policies, after the Obama administration pushed through United Nations sanctions against the country for launching a rocket last month.
The White House said the threat was ''needlessly provocative'' and would lead to further isolation and sanctions.
Mr Kim spoke at a meeting of foreign affairs and security officials discussing events on the Korean peninsula, KCNA said. US reaction to North Korea's rocket ''indicates that the US has reached its height in its anti-DPRK strategy'', the news agency said, citing a report to the meeting. DPRK refers to the country's official name, Democratic People's Republic of Korea.
The Punggye-ri nuclear site, where previous detonations were conducted in 2006 and 2009, may be in a continued state of readiness, the 38north website reported. Analysis of the area was based upon satellite imagery taken on January 23 and previous images, it said.
''Snowfall and subsequent clearing operations as well as tracks in the snow reveal ongoing activity at buildings and on roadways near the possible test tunnel,'' 38north reported.
A photo from January 4 shows a group of personnel, troops or security guards in formation in the yard of the administrative area near the test tunnel entrance, the institute said.
Imagery from December 24 shows a new pile of material near the command bunker in the same area, although the purpose of the material remains unclear.