SEOUL/BEIJING - If next month's planned summit with US President Donald Trump turns out well and leads to an easing of sanctions on North Korea, leader Kim Jong Un looks likely to tap on the experiences of China and Vietnam to open up his country's economy, reported a Japanese newspaper.

China and Vietnam have had experience introducing market forces into previously closed economies in the 1970s and 1980s respectively.

A North Korean delegation including Workers' Party of Korea Vice Chairman Pak Thae Song, a key aide of Mr Kim, arrived in Beijing on Monday.

The group has visited Zhongguancun, also known as China's Silicon Valley, and met with President Xi Jinping on Wednesday.

At his meeting with Mr Xi, Mr Pak said he had been entrusted with consolidating recent agreements between Mr Kim and Mr Xi at their recent summits as well as studying China's model of economic development and "reform and opening".

"We will play an active role in carrying out our party's new strategic line of prioritising economic development," Mr Pak was quoted as saying by Xinhua news agency.

Mr Pak was accompanied by senior party officials representing major provinces and cities of North Korea, reported Yonhap news agency.

Mr Kim is extremely interested in developing his country's economy, reported Nikkei Asian Review on Friday (May 18).

He decided at a party meeting last month to take back his signature two-track policy on nuclear development and economic growth and announced a new focus on the economy.

President Xi, on his part, has expressed support for North Korea's new shift to focus on the development of its economy.

Mr Kim, reported the Nikkei Asian Review, hopes to follow in the footsteps of China and Vietnam.

Under the open-door policy introduced by paramount leader Deng Xiaoping in 1978, China opened up its economy to foreign investors, setting the then impoverished economy on a trail-blazing path to become the world's second largest economy.

Critics at the time accused Deng of bringing capitalism back to China. But he argued that as long as the Communist Party remained in charge, the nation would not stray from its socialist ideals.

The Nikkei report said Mr Xi threw his support behind a similar change in North Korea when meeting with the young North Korean leader this month, their second meeting since the first in late March.

China is North Korea's most important trading partner and has long sought to convince its neighbour to follow Beijing's path of enacting free market reforms while maintaining tight single-party rule.

At his April 27 historic summit with South Korean President Moon Jae In, Mr Kim said that he aims for Vietnam-style reforms, the South's Maeil Business Newspaper has reported.

The Southeast Asian nation launched its Doi Moi campaign in 1986, paving the way for joining the World Trade Organisation in 2007 and continued economic growth. Its reforms have also been modelled after the Chinese approach.

Mr Kim, 34, attended a boarding school in Switzerland, spending some of his formative years in a free economy.

"Kim does not have personal qualms about capitalism," a South Korean diplomatic source said.

"They want Trump Tower" and McDonald's, South Korean presidential adviser Moon Chung In told CNN after the inter-Korean summit.

Normalising economic ties between the US and North Korea would provide a "real guarantee" for the survival of the government in Pyongyang, he said.

The North has high educational attainment and rich underground resources. Its economy could rack up consistent annual growth of 15 per cent for at least a decade or two once it opens up, according to former South Korean Unification Minister Lee Jong Seok.

North Korea is under sanctions imposed by the United Nations Security Council to stop its nuclear weapons and missile programmes.

Following the inter-Korean summit, the third since the end of the Korean War, the South Korean government said it was discussing how to finance possible economic projects with North Korea, although any projects with Pyongyang must first be approved by the international community.

"We're internally carrying out preparations, in terms of what to prepare, and how to cooperate with the international community, and how to finance (possible inter-Korea projects)," South Korea's finance minister s Kim Dong Yeon told reporters in Sejong on May 2.

"But we need support from the international community and need to watch the (upcoming) summit between the United States and North Korea," Kim said, without elaborating on specifics of any government financing.

South Korea's President Moon gave the North Korean leader a USB drive when they met face to face last month.

The USB contained an e-book and a short presentation illustrating Moon's so-called "New Economic Map" initiative which the Unification Ministry says is aimed at creating a "single market" for the two Koreas in order to "lay the foundation for unification" job creation and higher economic growth for both countries, reported JoongAng Ilbo.