North Korea and Russia have signed a strategic partnership cementing what North Korean dictator Kim Jong Un called a powerful "alliance" including the pledge of mutual defense should either country come under attack. 

"The comprehensive partnership agreement signed today provides, among other things, for mutual assistance in the event of aggression against one of the parties to this agreement," said Russian President Vladimir Putin.

Kim welcomed Russian President Vladimir Putin to Pyongyang in the early hours of Wednesday morning, when the two met on the runway at the capital's airport before sharing a limousine ride to the city center with a large police escort. 

As North Korean state media outlet KCNA described it in English, the two leaders were able to share their "pent-up innermost thoughts" during this conversation and agreed to deepen relations. 

Putin thankful for 'unwavering support'

In the first comments to emerge from the trip, Russian news agencies cited Kim as saying that Pyongyang intended to improve strategic cooperation with Moscow.

"The situation in the world is becoming more complicated and changing rapidly," Russia's TASS state news agency cited Kim as saying. "In this situation, we intend to further strengthen strategic contacts with Russia, with the Russian leadership."

"North Korea expresses full support and solidarity to the Russian government, army and people in carrying out a special military operation in Ukraine to protect sovereignty, security interests, as well as territorial integrity," Kim was quoted as saying, referring to the Russian invasion of Ukraine by Moscow's long-preferred term.

Putin expressed his thanks for Pyongyang's support of the Kremlin's policies in Ukraine.

"We highly appreciate your consistent and unwavering support for Russian policy, including in the Ukrainian direction," Russian state news agency RIA quoted Putin as saying at the beginning of talks with Kim.

Putin's first Pyongyang trip in 24 years

KCNA called the two countries' partnership an "engine for accelerating the building of a new multi-polar world" and said Putin's visit demonstrated the strength of the ties.

Since its full-scale invasion of Ukraine, Russia has used improving relations with North Korea as a way to needle Washington, while heavily sanctioned Pyongyang has benefitted from the promise of closer ties from Moscow.

The United States and its allies accuse North Korea of providing weaponry for Russia to use in Ukraine in exchange for help from Moscow with its space program — but Russia and North Korea reject charges of sanctions-defying weapons transfers.

Activity likely in Pyongyang on Wednesday

The two leaders left the airport in the Russian Aurus Senat limousine the Kremlin had gifted to North Korea earlier this year.

Russia reverted to the Soviet-era custom of using a homemade presidential limo in 2018 after a couple of decades of using Mercedes. The Aurus name hails from the Au chemical abbreviation for gold combined with RUS for Russia. 

The visit also comes amid typical tensions between North and South Korea. These were aggravated in recent weeks by the North dropping balloons filled with trash in the South and the South retorting by blaring propaganda through border loudspeakers. On Tuesday, Seoul said North Korean troops briefly crossed the border.  

NATO's Stoltenberg, in US, says Putin trip shows 'security is not regional' 

Meanwhile, NATO Secretary General Jens Stoltenberg is touring the US while Putin visits North Korea. 

At a joint press conference with Secretary of State Antony Blinken on Tuesday, Stoltenberg said Putin's trip showed the importance of expanding cooperation between the Western military alliance and partners in the Indo-Pacific. 

"Putin's visit to North Korea demonstrates and confirms the very close alignments between Russia and authoritarian states like North Korea, but also China and Iran," Stoltenberg said. 

"This demonstrates that our security is not regional. It's global. What happens in Europe matters for Asia, and what happens in Asia matters for us," he said. 

Stoltenberg went on to say that the "idea that we can divide security into regional theaters doesn't work anymore," as everything is "intertwined," requiring collective solutions. 

msh/sms (AP, Reuters)