The head of Indonesia's military says he reached a private agreement with the Chief of the Australian Defence Force to accept boat turn-backs as a way to defuse the diplomatic row over the policy.

General Moeldoko said late on Tuesday that boat turn-backs by Australia were ''justifiable'' as he had spoken to Australia's military commander on the issue - apparently referring to Chief of the Defence Force General David Hurley.

''He told me that Indonesia should understand if Australia drove back undocumented migrants attempting to enter the country using Indonesian boats or if any Indonesians were found aboard,'' General Moeldoko said. ''I have agreed. Therefore, we don't need to feel offended.''