Japan's All Nippon Airways (ANA) says it plans to buy a further 20 Boeing 787 aircraft

Japan's ANA Holdings said Tuesday it will buy 20 new Boeing 787-10 and 787-9 aircraft, with the planes expected to go into service between 2022 and 2025.

The order will be made up of 11 787-10 aircraft, which will serve domestic routes, and nine 787-9 planes for international destinations.

The price tag was not disclosed.

All Nippon Airways has been gradually replacing its Boeing 777s with 787s, citing better fuel efficiency and a reduction in noise emissions.

Once all 20 of the newly ordered planes go into service, ANA will operate some 103 787s, the firm said.

"Boeing's 787s have served ANA with distinction, and we are proud to expand our fleet by adding more of these technologically advanced ," said Yutaka Ito, executive vice president of ANA and ANA Holdings, in a statement.

"These planes represent a significant step forward for ANA as we work to make our entire fleet more eco-friendly and to reduce noise output," Ito added.