SEOUL - Former South Korean President Kim Dae-jung has cancelled a trip to Pyongyang planned for next week because of tensions over apparent preparations by North Korea for a ballistic missile test, an official in Seoul said on Wednesday.

"It is practically impossible for him to visit in late June because of the unexpected circumstances," South Korean official Jeong Se-hyun, who was negotiating the trip, told reporters.

The announcement comes as Seoul, Washington and Tokyo have said there is evidence North Korea may conduct a test-launch of a long-range missile, which the three have said would present a grave danger to regional security.

Kim, who orchestrated an unprecedented summit with North Korean leader Kim Jong-il in 2000, had hoped to use the meeting to help restart stalled six-country talks on ending Pyongyang's nuclear programmes.

Kim, who was president from 1998 to 2003, won the Nobel Peace Prize in 2000 for orchestrating the meeting in Pyongyang.

His visit began a rapid warming of ties between the two Koreas, which are still technically at war because only a truce was declared at the end of the 1950-53 Korean War.

Kim Jong-il has yet to reciprocate with a visit to the South.