Senior Chinese envoy in North Korea amid chill in ties to improve relations

The highest-level Chinese envoy to North Korea in two years arrived in the country's capital on Friday to try to improve relations that have soured over Beijing's tightening of sanctions and expressions of support for US President Donald Trump's calls for more pressure on the North to abandon its nuclear weapons programme.

Song Tao's official mission is to brief North Korean officials on the outcome of China's ruling Communist Party congress held last month.

He is visiting as President Xi Jinping's special envoy, according to Chinese and North Korean state media, but no other details about his itinerary or whether he will meet with North Korean leader Kim Jong Un have been announced.

The visit is seen as an effort by Xi to explore a new approach in relations and likely also reflects Xi's desire to head off further pressure from Washington.

China's relations with North Korea have deteriorated under Kim, who has ignored Beijing's calls to end the North's nuclear weapons and ballistic missile tests and return to disarmament talks.

North Korea staged its sixth nuclear test on September 3, detonating what it said was a hydrogen bomb, and most recently launched a ballistic missile on Sept. 15, firing it over the Japanese island of Hokkaido into the Pacific Ocean.

China, North Korea's largest trading partner, says its influence with Kim's government is often exaggerated by the US and others.

Beijing is opposed to measures that could bring down Kim's regime and lead to a refugee crisis along its border, and while enforcing harsh new U.N. sanctions targeting North Korea's sources of foreign currency it has called for steps to renew dialogue.

The visit comes as Joseph Yun, the US envoy for North Korea, met Friday with his South Korean counterpart, Lee Do-hoon, on the resort island of Jeju in South Korea.

"China, of course, has a big role to play on Northeast Asia security issues," Yun was quoted by South Korea's Yonhap news agency as saying, adding that he hopes China "regards the denuclearization as a critical goal. We do hope that special envoy will forward that goal."

Song's visit to North Korea also comes as China and South Korea are repairing their relations that soured over Seoul's deployment of a US anti-missile system.

South Korean President Moon Jae-in is to visit China next month for talks with Xi.

Song is the first ministerial-level Chinese official to visit North Korea since October 2015, when Politburo Standing Committee member Liu Yunshan delivered a letter to Kim from Xi expressing hopes for a strong relationship, although the respite in frosty ties proved short-lived.

Vice Foreign Minister Liu Zhenmin visited Pyongyang, North Korea's capital, in October last year. Song heads the Communist Party's International Department.