WASHINGTON - NORTH Korea's threats to test intercontinental ballistic missiles coupled with a leadership succession there makes for 'a potentially dangerous mixture,' the top US intelligence official said on Monday.

Director of National Intelligence Dennis Blair said North Korea's recent behavior was following a familiar pattern, but this time they were 'using more dangerous sorts of weapons, potentially intercontinental missiles and nuclear weapons.

'So although the pattern is familiar the level of risk is higher,' he said in remarks to business leaders with ties the intelligence community.

'I think overlaid on that are the succession concerns of the current leader,' Mr Blair said, referring to North Korea's long-time president Kim Jong-Il, who in May spiked regional tensions by testing a nuclear devise and a series of short-range missiles.

He also renounced the 1953 truce ending the Korean war.

'He had a stroke last summer and recently designated his son as his successor. So any time you have a combination of this behavior, doing provocative things in order to excite a response, plus succession questions you have a potentially dangerous mixture,' said Mr Blair.

Mr Blair added that the conflation of military activities and leadership questions were 'informing the activities the United States is involved in now working with the other countries in the six-party talks to try to put a ring around North Korea and handle it.' -- AFP