BANGKOK –

Japan's civil aviation agency has lifted a charter flight ban for Thai-registered airliners during April and May to help ease the impact on passengers, according to Air Chief Marshall Prajin Juntong, Thailand's transport minister.

Japan and Thai authorities were to sign a memorandum of understanding on Thursday about the suspension, on the condition that there will be stricter inspections of planes and flight schedules, Prajin told reporters on Wednesday.

Nearly 120,000 travelers seeking to go to Japan were expected to be affected by the flight bans, a Thai official said on Tuesday.

Airlines affected included national carrier Thai Airways International and long-haul, low-cost carriers like Thai AirAsiaX and NokScoot.

The Thai minister said Japan's aviation body has conducted safety checks on Thai carriers and three airlines — Thai VietJet, Jet Asia Airways and Thai Airways' unit Thai Smile — are substandard under the International Civil Aviation Organization (ICAO).

"Thai airlines have to cooperate with JCAB to solve the problem," Prajin said, adding that Thai airlines are still not allowed to increase the number of charter flights or change aircraft.

The airlines must submit their flight schedule in advance to the Japanese authorities, renew any expired pilot licenses and fix any malfunctioning equipment, he said.

Japan, along with South Korea and China, has banned Thailand-registered airlines from flying new charters and new scheduled flights to their countries because of safety concerns highlighted by ICAO.

Thai authorities also plan to go to South Korea, China, Australia and Germany this month to clarify the safety issue, the minister said.

In a statement, China's civil aviation authority said it had conducted safety checks on several Thai carriers, and had asked those with issues to rectify the problems within a specific period of time. It did not name the airlines or give details.