Tension has heightened following an announcement of military cooperation during Putin’s visit to Pyongyang last week.

The United States and its regional allies in Asia Pacific have strongly condemned the newly announced military alliance between Russia and North Korea.

The US, South Korea and Japan released a statement on Monday expressing “grave concern” over the defence pact signed last week during a well-publicised state visit to North Korea by Russian President Vladimir Putin.

A Pyongyang official, meanwhile, slammed the US for sending arms to Ukraine. Amid Moscow’s continuing war against its neighbour, the deal commits Russia and North Korea to provide aid in case the other is attacked.

The three allies said in the statement that the alliance should alarm “anyone with an interest in maintaining peace and stability on the Korean Peninsula, upholding the global non-proliferation regime, and supporting the people of Ukraine”.

It said the trio also pledged to “further strengthen diplomatic and security cooperation” to counter threats from North Korea, with Washington promising its military support for South Korea and Japan remains “ironclad”.

‘New World War’

The escalating rhetoric comes after the nuclear-powered USS Theodore Roosevelt aircraft carrier docked in the port of Busan as part of trilateral exercises with South Korea and Japan.

North Korea has long viewed such drills as practice for an invasion. Vice Minister of Defence Kim Kang Il on Monday called the arrival of the aircraft carrier to the Korean Peninsula a “very dangerous” show of force.

He asserted that it leaves the doors open for North Korea’s “overwhelming, new demonstration of deterrence”, state media KCNA reported.

One of North Korea’s top military officials, Pak Jong Chon, meanwhile insisted that Moscow has the “right to opt for any kind of retaliatory strike” if Washington continues to push Ukraine into a “proxy war” against Russia.

Moscow could be provoked to mount a stronger response, which could lead to a “new world war” should the US maintain its decision to allow its weapons to be used against Russia, he added.

North Korea has previously responded to joint US military drills with missile tests, and Pyongyang still maintains that it was forced to set up its nuclear weapons programme by US hostility.

South Korea said last week that its soldiers fired warning shots after several North Korean soldiers briefly crossed the border in the third such incident this month.

This comes amid escalating incidents that have also included North Korea sending trash-filled balloons over the border, and South Korea launching propaganda leaflets and using gigantic loudspeakers at the border.