China is temporarily closing its main road connection with North Korea, an official said on Friday.

Foreign ministry spokesman Geng Shuang said the Sino-Korean Friendship Bridge, or China-North Korea Friendship Bridge, across the Yalu River at the Chinese city of Dandong will be closed while North Korea repairs the approach road on its side.

Geng said that “after the maintenance, the bridge will reopen for passage,” but gave no date for the reopening or other details.

The bridge closure comes after state-owned airline Air China suspended flights Tuesday between Beijing and North Korea due to a lack of demand, deepening the North's isolation amid mounting UN sanctions.

Beijing is North Korea's only significant ally but has grown increasingly frustrated over its nuclear and missile tests that have brought a threat of war and chaos to China's north eastern border.

Chinese government orders all North Korean firms to close in China

In what was seen as a bid to improve relations, the head of the ruling Communist Party's International Department travelled to Pyongyang, North Korea's capital, last week.

Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Show all 6 1 /6 Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Photos released by North Korea show Kim Jong-un talking to subordinates next to a device thought to be the new thermonuclear weapon. There is no way of independently verifying the pictures STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb North Korea claims it has successfully tested an advanced hydrogen bomb which could be loaded onto an intercontinental ballistic missile AFP/Getty Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A diagram on the wall behind Mr Kim shows a bomb mounted inside a cone STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb North Korean leader Kim Jong-Un (C) attending a photo session with participants of the fourth conference of active secretaries of primary organisations of the youth league of the Korean People's Army (KPA) in Pyongyang STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A new stamp issued in commemoration of the successful second test launch of the "Hwasong-14" intercontinental ballistic missile KCNA via Reuters Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A new stamp issued in commemoration of the successful second test launch of the "Hwasong-14" intercontinental ballistic missile KCNA via Reuters

Few details have been released about his itinerary, including whether he met with North Korean leader Kim Jong-un. The trip followed a visit to Beijing earlier this month by US President Donald Trump, who renewed calls for China to step up pressure on North Korea to end its missile and nuclear programmes.