North Korea lauded its ties with historic ally China on Friday as Xi Jinping wrapped up a highly symbolic two-day visit to his nuclear-armed neighbour, with both countries facing deadlock in their negotiations with US President Donald Trump.

Kim Jong Un told the Chinese president that his visit was an opportunity to demonstrate "the immutability and invincibility of the DPRK-China friendship before the world", the KCNA news agency reported, using the abbreviation of North Korea's official name.

At a time when "serious and complicated changes are happening in international and regional situations", KCNA said, the two leaders agreed to "promote close strategic communication" and develop their "common interests".

Pyongyang pulled out all the stops to welcome Xi, the first Chinese president to visit in 14 years — a period in which Pyongyang has carried out five nuclear tests and launched missiles capable of reaching the entire US mainland.

China always prefers stability in its neighbourhood and the North's nuclear provocations strained the relationship between the Cold War allies, with Beijing backing UN sanctions on Pyongyang and Kim not visiting to pay his respects for more than six years after inheriting power.

But as he embarked on a flurry of diplomacy last year, Kim ensured that Xi — whose country is the North's key diplomatic supporter and main provider of trade and aid — was the first head of state he met.

Kim travelled to China three more times to meet Xi, and Pyongyang has been increasingly keen for the Chinese president to reciprocate.

Analysts say Xi, who left Pyongyang on Friday, intended to use the trip as a signal to Trump of his influence with Kim, a week before the G20 summit in Japan.

The world's top two economies are embroiled in protracted trade war and their leaders are expected to meet in Osaka.

Similarly nuclear negotiations between the North and the US are deadlocked, after the second summit between Kim and Trump broke up in Hanoi in February with the two unable to reach a deal on sanctions relief and what the North might give up in return.

But North Korean media did not carry comments by Kim reported by Chinese state broadcaster CCTV, which quoted him as saying that he was "willing to be patient" in the talks with the US, but wanted "the parties concerned" to meet him halfway.

Xi told him that China "positively evaluated" the North's efforts, CCTV said.

Jeung Young-tae, director of the Institute of North Korean Studies in Seoul, said the summit amounted to China giving Kim strong backing in the process.

"Xi is saying that he will help Kim resist pressure from the US and calling on Kim to stick to his demands," he told AFP.

Pyongyang has repeatedly called for Washington to adopt "a new method of calculation" for the negotiations, and Hong Min, a senior researcher at the South's state-run Korea Institute for National Unification said Xi's visit gave Kim a "political and diplomatic opening to resume talks with the US again".

– 'Friendly affection' –

North Korean authorities deployed tens of thousands of citizens to line the streets to welcome Xi, with KCNA saying they expressed their "friendly affection" for Chinese citizens who have "shared joys and sorrows" with them in the pursuit of socialism.

Kim and Xi rode together through the streets of Pyongyang in an open-topped Mercedes Benz limousine, and on Thursday evening Xi and his entourage were treated to a special performance of the North's Mass Games.

It featured multiple images of Chinese-Korean history and friendship on the backdrop – made up of thousands of children turning the pages of coloured books – slogans, and a portrait of Xi.

Songs in the show included "I love thee, China", and the Rodong Sinmun newspaper, the mouthpiece of the North's ruling party, carried front-page pictures of Kim and his wife Ri Sol Ju welcoming Xi.

Beijing sent millions of troops known as "Chinese People's Volunteers" to save the North from defeat during the Korean War, and Mao Zedong described their relations as "close as lips and teeth".

Nowadays Beijing sees the North as a strategic buffer, keeping the 28,500 US troops in South Korea far from its borders.

Big picture: Xi on show in Pyongyang
Pyongyang (AFP) June 21, 2019 –

Xi Jinping has loomed large over China since becoming president, with a huge personality cult growing around his leadership, but in Pyongyang he looked bigger than usual when a giant portrait was unveiled at a propaganda event.

The Chinese president, who is making the first trip by a Chinese head of state to North Korea in 14 years, was treated to a special performance of the spectacular "Mass Games" by his host Kim Jong Un.

It is a show that could only be mounted by a country as single-minded as the North — Guinness World Records lists a 2007 performance as the world's largest gymnastic display, with 100,090 participants.

Months in the preparation, the Mass Games feature tens of thousands of people in synchronised displays enacting scenes from Korean history and modern life.

Behind them, around 15,000 children turn the coloured pages of books in sequence to create an ever-changing backdrop of giant images rippling across one side of the cavernous May Day stadium — an analogue version, on a giant scale, of a usually digital solution.

At one point during Thursday's performance — a special version called "Invincible Socialism" — the backdrop displayed a portrait of Xi against a Chinese flag, pictures on the website of the Rodong Sinmun, the official mouthpiece of the North's ruling party, showed.

Another image displayed a slogan in Chinese: "Long live the unbreakable friendship and unity between the two peoples of DPRK and China."

DPRK is the abbreviation of North Korea's official name.

Songs included "New China cannot exist without the communist party", "I love you China" and "Red flag is fluttering".

Xi has consolidated power to become China's most powerful leader since Mao Zedong, with the communist party's propaganda machine building a cult of personality around the president.

His face or name dominate the front pages of the newspapers every day, and his agenda leads every evening news programme.

Souvenir shops sell trinkets bearing his image and government workers have been encouraged to download an app dedicated to him that rewards users with points for the time they spend reading his speeches, watching videos of him and taking quizzes about the general secretary of the Communist Party.

– 'Land of the People' –

For its part, the North lionises Kim and his predecessors — his authority derives from his status as the third generation of his family to rule.

Portraits of his grandfather Kim Il Sung — the founder of the Democratic People's Republic of Korea — and father Kim Jong Il are ubiquitous, found in every office, workplace, schoolroom and home in the country.

But portraits of Kim Jong Un himself are a rarity — it was notable that one was displayed at Pyongyang airport alongside Xi's when the visitor arrived, with both images again hanging above the rostrum where the two men watched the display.

When the Mass Games began their 2019 run with a show titled "The Land of the People", the backdrop display included a portrait of Kim.

Afterwards "he called creators of the performance and seriously criticised them for their wrong spirit of creation and irresponsible work attitude", lecturing them on "correctly implementing the revolutionary policy of our Party on literature and art", the North's official KCNA news agency reported, and performances were later suspended.

The North has never been explicit about what infuriated Kim, and it was not clear whether the backdrop showed any portraits of him on Thursday — but no such images were included in the pictures on the Rodong Sinmun website.