Japan's Foreign Ministry has lodged a complaint against the Myanmar military, saying that it confirmed the armed forces had misused ships provided as part of a Japanese aid program.

The foreign ministry said Japan gave Myanmar three ships between 2017 and 2019 for the purpose of improving its waterborne transport capability.

The provision was arranged under the Japanese government's Official Development Assistance scheme.

Local people had used the ships for their commutation or other civilian purposes.

But reports came out last year on partial use of the ships for military purposes.

The foreign ministry looked into the claim and concluded that two of the vessels were used in improper ways such as for transporting troops and weapons.

The ministry demanded the Myanmar military work to prevent a recurrence.

Foreign Ministry press secretary Ono Hikariko expressed deep regret over the issue at a news conference on Friday.

She said Japan will keep working to prevent such an incident, to grasp actual usage, and to promote proper application of Japanese aid.