The Japanese government plans to sign on to a global deal on curbing emissions of carbon dioxide from commercial aircraft on international routes, officials said Saturday.

The deal, which aims to cap emissions at the levels in 2020, could increase costs for Japanese airlines because they may have to introduce more fuel-efficient aircraft. Some of the costs might be passed on to air travelers.

The deal is being discussed at the United Nations' International Civil Aviation Organization and is expected to be adopted at its general meeting late this month. The United States, China and European countries are also expected to sign on to it.

Airlines in participating countries would need to consider introducing eco-friendly aircraft and using more biofuel, which adds less carbon dioxide to the atmosphere than fossil fuels. Airlines that cannot meet emissions goals would have to offset their emissions by buying carbon credits through an emission trading system.

With Japanese airlines likely having to tap such a trading system, an official of the Land, Infrastructure, Transport and Tourism Ministry said the airlines "might have to shoulder as much as tens of billions of yen a year in costs in the future."

The government is expected to announce its intention to sign on to the global deal sometime before or after transport ministers from the Group of Seven industrialized countries meet from Sept. 23 to 25 in the Nagano Prefecture town of Karuizawa.