During the meeting at the headquarters of North Korea's Central Military Commission, Kim Jong Un delivered what state media described as an "historic" address. The official Korean Central News Agency reported that he used the speech to issue "important" guidelines on how to bolster the country's armed forces and safeguard the country's security.

It said the senior party and military leaders present at the meeting "evinced their firm determination to unconditionally and thoroughly implement the militant tasks set forth" by Kim Jong Un. Although the report was published on Sunday, KCNA did not say when the meeting was actually held.

Observers see Kim's speech as an indication that a nuclear test could be imminent. North Korea officially announced its intention to carry out a third nuclear test last month.

Kim's reported speech also follows a series of statements issued by Pyongyang over the past few days, in which it vowed to retaliate for the latest round of United Nations Security Council sanctions, which were tightened last month following a long-range rocket launch.

The United States, South Korea and their allies accuse North Korea of using that launch last December as a pretext to test ballistic missile technology, something it was banned from doing under previously existing sanctions. Pyongyang claimed there was no military element to the launch, and that it was used to send satellites into orbit.

Deja vu

Analysts also say they see similarities between developments in the past few days and weeks and the time leading up to its previous two nuclear tests. Both the 2006 and 2009 tests came after the international community had ramped up sanctions against Pyongyang after similar rocket launches to the one conducted late last year.

Recent satellite images have also revealed what analysts said could be work being done on a tunnel in a mountainside, where it's thought the test could be conducted.

All of this has raised tensions on the Korean Peninsula. On Sunday, South Korean President Lee Myung Bak met with his top security advisors and urged them to "stand well prepared" for a possible nuclear test, according to the South's Yonhap news agency. It also reported that Seoul's top nuclear envoy left for Beijing on Sunday, where he was to hold talks aimed at getting China to use its influence to try to persuade Pyongyang to a scrap the planned test.

On Monday, the US and South Korea are to begin conducting three days of joint naval exercises, expected to be held in the Sea of Japan.

pfd/hc (AFP, AP)