Six firefighting teams in Kuwait are battling a fire at Kuwait International Airport's new T2 project, the Kuwait Fire Force said on Twitter.
Authorities have yet to say if the fire has led to casualties.
The chief of Kuwait's Fire Force, Col Mohammad Al Ghareeb, told The National the affected building was under construction.
Flight tracking data showed planes arriving at and departing from the airport throughout Monday morning. Several early morning flights took off with slight delays, but Kuwait's Directorate General of Civil Aviation said air traffic was normal and had "not been affected" by the fire.
Ahmad Saad Al Saleh, spokesman at the Ministry of Public Works, said a "limited fire" broke out in a section of the T2 project on Monday morning. He said firefighting teams were working to put out the flames.
The T2 terminal is expected to provide 15,000 jobs to Kuwaitis. Construction in the first of three phases has passed the halfway point, the Ministry of Public Works said in September last year.
Minister Rana Al Fares said the new facility would offer a "major boost" to aviation in Kuwait, state news agency Kuna reported.
Once completed, the new terminal will have 5,000 car parks and an annual passenger capacity of 25 million, as well as the ability to accommodate 51 aircraft, Ms Al Fares said.