A North Korean "friendship" group led by a high-ranking ruling party official in charge of economic policy is visiting China, state-run media reported Tuesday, around a month ahead of Pyongyang's summit with the United States.

At Beijing International Airport, the delegation headed by Pak Tae Song, vice chairman of the Workers' Party, was greeted by an official of China's ruling Communist Party and North Korea's ambassador to China, the Korean Central News Agency said.

KCNA did not report details of the group's activities, but high-ranking officials from Beijing and Pyongyang are believed to have exchanged views on the summit to be held between North Korean leader Kim Jong Un and U.S. President Donald Trump on June 12 in Singapore.

(Pak Tae Song, KNS/Kyodo)

Relations between China and North Korea have drastically improved recently. Kim traveled to Beijing in March to hold talks with Chinese President Xi Jinping, and last week the two leaders met again for two days in the northeastern Chinese city of Dalian.

Earlier this month, Chinese Foreign Minister Wang Yi visited Pyongyang.

Kim's visit to Beijing in March was his first foreign trip since becoming North Korea's supreme leader following the death of his father Kim Jong Il in December 2011.

China, North Korea's main economic lifeline, had been increasing economic sanctions against Pyongyang since late last year as Kim continued to develop ballistic missiles and nuclear weapons in defiance of international warnings, worsening bilateral ties.

(Park, center right, was pictured on May 14, 2018 as he left Pyongyang International Airport for Beijing. KCNA/Kyodo)  

On Monday, a person who appeared to be a high-ranking North Korean official arrived in Beijing and was staying at the Diaoyutai State Guesthouse, where foreign dignitaries usually are accommodated on visits to China's capital, according to a source close to the matter.

The delegation led by the person visited Zhongguancun in Beijing, which is known as "China's Silicon Valley," the source said, adding North Korea and China may be trying to bolster their economic exchanges. Kim also visited the area in March.