SEOUL, Oct 13, 2023 (BSS/AFP) - Pyongyang on Friday slammed a South Korean port visit by the aircraft carrier USS Ronald Reagan, saying it showed Washington had reached "the most serious phase" of preparations for a potential nuclear war.

The nuclear-powered carrier is currently docked in the southern port city of Busan following a joint two-day maritime exercise conducted alongside ships from South Korea and Japan earlier this week.

State media outlet KCNA called the drills, which simulated the interception of North Korean smuggling vessels, an "undisguised military provocation".

They followed the most recent edition of the annual US-South Korean Ulchi Freedom exercises, which Pyongyang views as a rehearsal for invasion.

Seoul's joint chiefs of staff have announced additional drills will be conducted next week.

"The US scheme for nuclear attack on the DPRK and its implementation have reached the most serious phase of systematization and visualization," Friday's KCNA commentary said.

"It is as clear as noonday what result will be brought to the Korean peninsula, where huge armed forces and nuclear weapons are standing in confrontation with one another, even if a spark is produced," it added.

North Korea has carried out a record-breaking number of missile launches this year in defiance of international sanctions, and Pyongyang last month enshrined its status as a nuclear power in its constitution.

The North has also pledged to launch a military spy satellite into orbit this month after two earlier failed attempts, most recently in August.

With attempts at diplomacy stalled, South Korean President Yoon Suk Yeol has made a concerted effort to improve historically strained ties with Japan, the country's former colonial ruler.

In August, Yoon and Japanese Prime Minister Fumio Kishida took part in a three-way summit hosted by US President Joe Biden at Camp David, agreeing to a multi-year plan of regular joint exercises.

North Korean leader Kim Jong Un has described the burgeoning defence alliance as "the worst actual threat".