BEIJING (AFP) - A North Korean delegation has visited Beijing to learn about China's experience in economic reform and opening up, the foreign ministry said Tuesday (May 15), the latest diplomatic outreach by the isolated regime.

The Cold War-era allies have stepped up contacts in recent weeks as North Korean leader Kim Jong Un prepares for a historic summit with US President Donald Trump in Singapore on June 12.

China said Pak Thae Song, vice-chairman of the Central Committee of the ruling Workers' Party of Korea, visited Beijing on Monday at the invitation of the Chinese Communist Party.

"This visit is a concrete example of the important consensus between (Communist Party) General Secretary Xi Jinping and Chairman Kim Jong Un," foreign ministry spokesman Lu Kang told a regular press briefing, confirming media reports about the trip.

The delegation came to "learn about the achievements of China's domestic economic development and reform and opening-up process, and promote an exchange of experience between the two parties on governance issues," Lu said.

Analysts have said Kim's promise last month to build "socialist economic construction" could herald more Chinese-style economic reforms, which transformed the communist-led country into the world's second largest economy.

Kim used the phrase when he declared that his regime had completed the development of its nuclear arsenal and no more atomic or missile tests were needed.

The delegation visited Beijing a week after Kim met Xi in China's northeastern port city of Dalian - his second trip to China in less than two months.

Pyongyang and Beijing are seeking to mend frayed ties as a diplomatic thaw in the region intensifies.

Relations fell to a new low in the past year as Beijing, angered by Pyongyang's nuclear and missile tests, supported a series of United Nations sanctions against its ally.

But Beijing is keen to avoid being sidelined in the wake of Kim's historic summit last month with South Korean President Moon Jae In and ahead of his Trump summit.

Experts say Kim needs to maintain good relations with his country's main patron as the Trump meeting looms.

Kim, who picked Beijing to make his maiden official trip abroad in March, has also invited Xi to visit North Korea.