SEOUL • North Korean leader Kim Jong Un is planning a "prime time" nuclear weapons push next year to take advantage of leadership transitions in South Korea and the United States, a high-ranking defector said yesterday.

In his first press conference since fleeing his post as North Korea's Deputy Ambassador to Britain in August, Mr Thae Yong Ho said Mr Kim had issued a directive at a rare ruling party congress in May to "complete" nuclear development by the end of next year.

"With South Korea holding presidential elections and the US undergoing an administration transition, the North sees 2017 as the prime time for nuclear development," Mr Thae told local reporters. "That's based on a calculation that the US and South Korea will not be able to take physical, military measures because they are tied up with domestic politics."

North Korea carried out two nuclear tests this year and numerous missile launches in pursuit of its ultimate goal of a deterrent capable of delivering a nuclear warhead to the US mainland.

Analysts are divided as to how close Pyongyang is to realising that ambition, especially as it has never successfully tested an inter-continental ballistic missile.

But all agree it has made enormous strides in that direction since Mr Kim took over as leader from his father, Kim Jong Il, who died in December 2011.

AGENCE FRANCE-PRESSE