The West watches anxiously as Vladimir Putin and Kim Jong Un ...

Russian President Vladimir Putin's visit to North Korea on Wednesday was filled with lavish ceremony and pomp, but the world will be closely watching after the two nations vowed to assist each other should either country face "aggression".

Mr Putin and North Korean leader Kim Jong Un signed a new partnership in Pyongyang that included a mutual defence pledge.

The full wording of the vague agreement has not yet been released but could potentially revive a treaty signed between North Korea and the former Soviet Union in 1961.

Mr Putin's first visit to North Korea in 24 years was the culmination of a recent strengthening of relations between the two states.

Mr Kim described the new relationship as an "alliance" while Vladimir Putin said it was a "breakthrough document".

Vladimir Putin and Kim Jong Un signed a new partnership deal in Pyongyang.(Sputnik/Gavriil Grigorov via Reuters)

The two nations, increasingly isolated on the global stage, can provide value to each other.

Washington says North Korea has unlawfully sent dozens of ballistic missiles and over 11,000 containers of munitions to Russia in support for its war in Ukraine.

North Korea meanwhile wants Russian knowledge and expertise to assist its missile and nuclear programs, as well as economic assistance and Russian oil.

Mr Putin said he did not "exclude the development of military-technical cooperation with the Democratic People's Republic of Korea".

Shunned by the West, Vladimir Putin has few options when it comes to forming alliances that will help him prosecute his war in Ukraine.

University of Oxford lecturer Edward Howell says the partnership with North Korea represents an anti-West block.

"It sends a clear signal to the West of the emergence of an anti-Western, anti-democratic coalition of states," he said.

"North Korea gains cash, food and technological assistance, and Russia gains ammunition."

Vladimir Putin is eager to secure missiles and munitions for his war in Ukraine.(Sputnik/Gavriil Grigorov via Reuters)

Professor Charles Kupchan, a senior fellow at the Council on Foreign Relations, says the partnership also confirms the highly fractured state of geopolitics.

"In some ways, we are beyond what we saw in the Cold War, because the Cold War was mostly cold," he said.

"We've got a hot war in Ukraine, and I think the visit of Vladimir Putin to Pyongyang is a sign of the depth and gravity of the rift that has opened up between Russia and the West."

He says the pact is concerning for the United States and complicates matters both in Ukraine and on the Korean peninsula.

"We're not talking about a weapon here and there, we're talking about hundreds of thousands if not millions of artillery shells [coming from North Korea]," he said.

"It will also make it more difficult for the United States and its partners to make progress in denuclearising North Korea."

Vladimir Putin and Kim Jong Un attend an official welcoming ceremony.(Sputnik/Vladimir Smirnov via Reuters)

China, North Korea's most important economic partner and an ally of Russia, has remained silent so far.

"Is China going to throw its lock in with Russia and North Korea, or is it going to try to straddle and avoid the slippery slope of heading towards a new Cold War with the United States — I think right now it's difficult to tell," Professor Kupchan said.

North Korea put on quite the welcome for Vladimir Putin.

Kim Jong Un met Mr Putin at the airport in the early hours of Wednesday morning local time.

North Korea put on a lavish welcome for Vladimir Putin's first visit to the country in 24 years.(Sputnik/Gavriil Grigorov via Reuters)

During the day, Mr Putin was welcomed with a ceremony at Pyongyang's main square.

Cheering crowds gathered for Mr Putin's visit, some waving North Korean flags and holding posters showing Mr Putin.

Buildings were also decorated with giant Russian flags and portraits of Mr Putin.

The Russian president drove Kim Jong Un in a luxury Russian limousine, before the pair switched places.(Sputnik/Gavriil Grigorov via Reuters)

Mr Putin gifted Mr Kim with a luxury Russian limousine, even driving him around before they switched places.

Mr Putin also gifted Mr Kim a tea seat and a naval officer's dagger, while Mr Kim's presents to Mr Putin included an artwork depicting the Russian leader.

Later, the pair watched a concert together.