The PM is scheduled to attend the 78th session of the UN General Assembly (UNGA) at the UN headquarters from September 18-24.
He will first participate in the Leaders' Dialogue 6 on “Mobilising Finance and investments and the means of implementation for Sustainable Development Goals achievement”.
Earlier on Monday, Srettha and his team took TG 8832 charter flight from Suvarnabhumi Airport, which refuelled at Haneda Airport in Japan before heading to New York.
The premier, Foreign Minister Panpree Pahitanukorn and government officials sat in the aircraft's business class, contrary to some claims that they had travelled first class.
“I sat with my team in business class to stay together and save cost,” Srettha said.
He said taking Thai Airways International flight is cheaper than taking a Royal Thai Air Force (RTAF) jet, adding that it helped boost transparency on budget expenditure.
He said the flight was comfortable, even though he had to stretch his legs to the fullest due to his height. Srettha was seen reading the UNGA 78 agenda during the flight.
“I do not want people to think that the prime minister must choose the best option, but I instead think of how to maximise the budget," he said.
Echoing Srettha, secretariat of the Prime Minister confirmed that taking Thai Airways International flight was cheaper, adding that RTAF aircraft was currently under maintenance.