The announcement came a day after China’s aviation authority, the Civil Aviation Administration of China (CAAC), rolled back restrictions on foreign airlines, including U.S. carriers, that were in place to prevent imported coronavirus cases to China, where the virus outbreak is largely under control.

That rollback itself happened a day after the Trump administration said it would ban seven major Chinese airlines from the U.S. to retaliate against China’s foreign airline restrictions, which applied to U.S. carriers Delta Air Lines, United Airlines, and American Airlines. (Delta and United had asked to resume flights to China this month; American plans to restart its service at the end of October.)

The CAAC did not name specific airlines or the U.S. in particular, but the timing of the announcement appeared to be a concession from China that may ease rising tensions between the two countries.

Yet a trade group representing U.S. carriers said the change was not enough, and the airlines wanted a higher flight frequency than the promised once-a-week. “While the Chinese response to the Department of Transportation is a step toward parity for U.S. carriers, more is needed to achieve the goals of the agreement,” the group Airlines for America said Thursday, referring to the U.S.-China Civil Air Transport Agreement of 1980.

Four Chinese airlines—Air China, China Eastern, China Southern, and Xiamen Airlines—were granted flights to the U.S. for June. If the Wednesday order were to have gone through, those four carriers’ flights—each carrier was scheduled for one flight a week—would have been suspended.

“[W]e will allow Chinese carriers to operate the same number of scheduled passenger flights as the Chinese government allows ours[,]” the U.S. DOT statement said.

According to the DOT, the 1980 deal says China must allow one U.S. carrier one flight to China for every flight to the U.S. by a Chinese carrier.

China’s relaxed flight arrangements will allow Delta and United to fly to a city of their choice in China starting June 8. China’s aviation regulator, the CAAC, also said that foreign airlines will be able to fly to China twice a week instead of once if all their passengers test negative for the coronavirus for three consecutive weeks.

If five or more passengers on a flight test positive on arrival in China, the CAAC said, that airline will be banned from flying into the country for one week; if 10 or more people test positive, the ban increases to four weeks.

International flights will be able to land in 37 Chinese cities, the CAAC said. Besides U.S. airlines, European carriers like Lufthansa and Finnair had also applied to resume China flights in June, but those two airlines told Caixin in late May that they had not yet received a verdict.

“When the risks are under control and adequate guarantees are received, the number of flights from eligible countries can be appropriately increased,” the CAAC said.