North Korea's nuclear tests 'linked to succession plans'

North Korea's nuclear and missile tests are linked to the succession plans of its 'inhumane'" regime, South Korea's defence chief has said.

Defence Minister Lee Sang-Hee warned the military to stay on guard and "sternly punish" any border provocation, in a message in an army-run newspaper confirmed by his ministry today.

Another South Korean newspaper, Chosun Ilbo, said Seoul has given the United States information on the North's foreign bank accounts.

It said this was an apparent sign that Washington is preparing financial punishment for Pyongyang's May 25 nuclear test.

In New York, UN Security Council members continued debate on a new resolution to toughen sanctions but said they need more time for agreement.

Lee said leader Kim Jong-Il is obsessed with handing power to his son and this is the motive for nuclear and missile tests which have shaken the region over the past two months.

"Bent on his effort to engineer a hereditary power succession, Kim Jong-Il is pushing ahead with nuclear development, missile launches and moves to raise tension," Lee said.

He described the North's leadership as "immoral, irresponsible and inhumane" towards its own people.

Dong-A Ilbo newspaper said the South has doubled its naval forces near the disputed border with the North in the Yellow Sea, where bloody clashes broke out in 1999 and 2002. Military authorities refused to comment.

Chosun said Seoul had provided details of 10-20 bank accounts which South Korean companies or civic groups use to remit money to the North for business or aid projects there.

Government officials could not immediately comment on the report.

The paper said the accounts are suspected of being used for transactions related to counterfeiting, drug dealing and money laundering.

Most are in Chinese banks but some are in Switzerland or elsewhere, it said.

The five permanent Security Council members plus Japan and South Korea held more talks yesterday.

"We're making progress but we are not done yet," US ambassador to the UN Susan Rice told reporters. "I'm hopeful that this will be concluded soon."

Diplomats say the US and its allies are trying to persuade China and others to support tougher cargo inspections, a tighter arms embargo, a possible freeze on North Korean assets abroad and denial of access to international banking and financial services.

In what US President Barack Obama has called "extraordinarily provocative" actions over the past two months, the North has test-fired a long-range rocket, detonated a nuclear weapon underground and fired short-range missiles.

It also renounced the armistice on the Korean peninsula and threatened possible attacks on South Korea, prompting a military alert.

US and South Korean officials say the North also seems to be preparing another long-range missile test.

Russia's military has information about a planned ballistic missile launch by the North, a senior military source said.

"We have certain information on the type and characteristics of the rocket. However there is no precise information on the timing of its launch," the source said.

Analysts say the ailing Kim, 67, is projecting an image of strength to bolster his authority as he prepares his youngest son Jong-Un for an eventual takeover.

Obama has signalled a firmer policy towards the North after almost six years of now-stalled six-nation nuclear negotiations. The US is "not intending to continue a policy of rewarding provocation," he said Saturday.

But the plight of two US reporters jailed Monday by Pyongyang is complicating Washington's response.

A court sentenced Laura Ling and Euna Lee to 12 years of "reform through labour" for an illegal border crossing and an unspecified "grave crime."

Border guards detained them on March 17 while they were researching a story about refugees fleeing the North.