North Korean leader Kim Jong Un (L) inspects a newly built submarine at an undisclosed location. Photo: KCNA VIA KNS / AFP

The submarine will be deployed to the East Sea, also known as the Sea of Japan, the North's official KCNA news agency said on Jul 23, without disclosing its specifications or the location of the inspection.

"The Supreme Leader learned in detail about its operational and tactical data and combat weapon systems," KCNA said.

The inspection comes a week after Pyongyang warned next month's US-South Korea military drills "will affect" proposed working-level nuclear talks with Washington that leader Kim and President Trump agreed to pursue during an impromptu meeting in the Demilitarised Zone that pides the two Koreas on Jun 30.

But no meetings between the two sides have taken place since then.

North Korean leader Kim Jong Un inspects a new submarine in this undated photo from the state-run Korean Central News Agency.

There are close to 30,000 US troops stationed in South Korea and their annual drills with tens of thousands of South Korean soldiers have always infuriated the North - with Pyongyang slamming the manoeuvres as rehearsals for invasion.

The North in the past week condemned the upcoming military exercise as "blatant pressure" on Pyongyang and a "violation of the spirit" of the joint statement Trump and Kim signed at their historic meet in Singapore last year.

President Trump meanwhile said on July 22 there was "very positive correspondence with North Korea".

"Again there's no nuclear testing, there's no missile testing, there's no nothing," he said./.

VNF/AFP