The countries had business reopened between Dandong and Sinuiju in North Korea in January after a two-year hiatus as the North imposed one of the world’s most restrictive pandemic border closures despite pressure on its slumped economy.

Chinese Foreign Ministry spokesman Zhao Lijian said on Friday that the decision to suspend cargo services was taken “in light of the current epidemic situation in Dandong”, but he gave no further retail.

The Dandong city government on Monday ordered all residents to quickly return home and stay there to stem the spread of the virus. He said the government would make strenuous efforts to provide daily needs for residents, but made no mention of ties to North Korea and did not say when the lockdown would be lifted.

While many countries are dropping restrictions and trying to live with the virus, China is sticking to a “zero-COVID” approach, which requires mass testing and lockdowns and keeping its international borders largely closed.

North Korea’s decision to tentatively reopen cross-border trade with China, its main ally and economic lifeline, may have reflected a growing urgency in its need for outside help.

North Korea still claims to have a perfect folder to keep COVID-19 of its territory – a claim widely doubted. But closing its border to almost all trade and visitors for two years has further shocked an economy already damaged by decades of mismanagement and crippling US-led sanctions against its nuclear weapons and missile program.

Experts say the North has reportedly focused on importing fertilizers to boost food production, factory goods to boost dismal industrial production and construction materials to support ambitious development projects that leader Kim Jong One presents as major achievements.

The North has been accelerating its weapons testing in recent months, including its first test of an intercontinental ballistic missile since 2017 in March, as it rekindles a tightrope to pressure the United States into accepting it as a nuclear power and lifting punishments. South Korea’s Unification Ministry, which handles inter-Korean affairs, did not immediately provide further details on the suspension of cargo traffic between North Korea and China.