Air China is to resume regular flights between Beijing and Pyongyang after a six-month hiatus, in the latest sign that the “maximum pressure” campaign on North Korea may be easing.

China’s flagship carrier will resume services on Wednesday after halting them in November, a spokesman for the company confirmed in a WeChat message. The resumption is a market-oriented decision, he said.

The flights were stopped after North Korea’s nuclear test and missile launches last year. But ties have since warmed, with leaders Xi Jinping and Kim Jong Un holding meetings in March and May. The apparent detente seems at odds with assertions that pressure should remain on North Korea until it shows demonstrable progress toward denuclearization.

U.S. Secretary of Defense James Mattis said in Singapore on Sunday that all United Nations Security Council resolutions on the regime must stay in place. “North Korea will receive relief only when it demonstrates verifiable and irreversible steps to denuclearization,” he said.

Meanwhile U.S. President Donald Trump has taken to using a softer tone on the “maximum pressure” campaign, saying Friday: “I don’t want to use that term. Because we’re getting along.”

Property prices on the North Korean border with China appear to have been rising in response to the apparent thawing in relations. New-home prices in Dandong, a city that sits across the Yalu River from North Korea, gained a record 2 percent in April from March, according to data from China’s National Bureau of Statistics.

Dandong is a barometer on how well the sanctions are working to starve North Korea of funds. About 80 percent of North Korea’s international trade is with China, much of it through the frontier town filled with shopkeepers, smugglers and real-estate dealers whose fortunes rise and fall with the trade across the River Yalu.