On June 7, Environment Minister Han Wha-jin signed a Memorandum of Understanding (MOU) at Seoul City Hall regarding the conversion of Seoul city buses and airport buses into hydrogen buses. During the signing ceremony, the Minister stated, "The introduction of hydrogen airport buses would serve as an opportunity to promote Korea's eco-friendly image globally."

On the same day, the Minister, along with Seoul Mayor Oh Se-hoon and key corporate officials, took a test ride on a hydrogen airport bus in Seoul. Together, they discussed the safety and the need for the adoption of hydrogen airport buses.