SEOUL: North Korean leader Kim Jong Un has supervised the testing of a "high-tech" new weapon, Pyongyang's state media reported on Friday, in an apparent bid to apply pressures on the United States and South Korea amid a stalemated nuclear diplomacy.

"Kim Jong Un inspected the testing of a newly developed high-tech tactical weapon at the Academy of National Defence Science,"  Yonhap news agency said.

It said the test was successful but did not specify the type of device involved.

The "high-tech tactical weapon" had been developed over a long period and "builds impregnable defences of our country and strengthens the fighting power of our people's army", it added.

Pyongyang's suspension of nuclear weapon and ballistic missile tests has been key to this year's rapid diplomatic developments and North Korean-US negotiations and has been repeatedly praised by President Donald Trump.

Reports said "it didn't appear to be a nuclear device or a long-range missiles targeting the mainland US, a string of which last year had many fearing war before the North turned to engagement and diplomacy early this year. Still, any mention of weapons testing could influence the direction of currently stalled diplomacy between Washington and Pyongyang that's meant to rid the North of its nuclear weapons".

Since November last year, the North hasn't publicly tested any weapons. But in recent days Pyongyang reportedly expressed anger at US-led international sanctions and ongoing small-scale military drills between South Korea and the United States. Earlier this month, North Korea's foreign ministry warned it could bring back its policy of bolstering its nuclear arsenal if it doesn't receive sanctions relief.

Trump and Kim met in a historic summit in Singapore in June, where they signed a vaguely-worded document on denuclearisation of the peninsula.

Progress has since stalled as Washington and Pyongyang spar over the meaning of the document, and a return to testing would cast grave doubts over the future of the process.

"That pit of dread you felt in your stomach when you read this is your reminder that the DPRK missile test pause is voluntary, partial, and can fail without notice if it isn't explicitly codified," Adam Mount of the Federation of American Scientists tweeted in response to the report, using the country's official acronym.
 

(WIth agency inputs)