MONTREAL -- Saskatoon International Airport is the "most improved airport" in North America, according to the latest annual rankings by Airports Council International.

Other airports similarly lauded by the trade association were in Nairobi, Kenya (most improved in Africa); Denpasar, Bali (Asia-Pacific); Istanbul (Europe); Kingston, Jamaica (Latin America-Caribbean); and Dammam, Saudi Arabia (Middle East).

Stephen Maybury, president and CEO of Saskatoon Airport Authority, said "significant investments" have been made at his airport to improve conditions for passengers.

"Completion of the $53-million terminal expansion in early 2015 has created space for guests to be comfortable and to enjoy the new experiences the airport has to offer," he said Monday in a release. Further improvements are planned to parking and other terminal services, he said.

Ottawa tied with several U.S. airports for second place in the ACI ranking for best airport overall in North America, while Billy Bishop Toronto City Airport tied for third. Indianapolis was named No. 1 in the category.

Seoul Incheon and Singapore tied for first among the world's busiest airports (over 40 million passengers per year).

Among other winners: Skopje, Macedonia, was named best small airport in Europe (under two million passengers per year); London Heathrow was best large airport in Europe (over 40 million); and Guayaquil, Ecuador, was best airport overall in Latin America-Caribbean.

The ACI Airport Service Quality program is based on assessing passengers' satisfaction at over 300 airports worldwide, covering elements such as check-in, security and food and beverage options.