UN atomic watchdog head Yukiya Amano said Monday he will seek a third term in office beyond 2017, saying the agency needs "continuity" to face difficult times ahead.

Amano said that the "huge challenges" facing the International Atomic Energy Agency include North Korea's nuclear weapons and stopping nuclear materials from falling into the wrong hands.

"In order to address these challenges, continuity and unity are very important. This is the reason why I am running for a third term," the veteran Japanese diplomat, 69, told a regular news conference.

He added that several member states had encouraged him to run.

Amano has been director general of the Vienna-based IAEA since December 2009 and his current term expires in November 2017.

Amano was a contentious choice when first elected nearly seven years ago, with many countries seeing him as a US puppet.

US diplomatic cables quoted by WikiLeaks described him as being "solidly in the US court on every key strategic decision".

But four years later, he appeared to have won over many detractors and was easily re-elected in 2013.

So far, diplomats in Vienna have been guarded on whether they will support him staying on.