Australian Defence Minister David Johnston said Tuesday that his country is "doing everything we can" to search for debris of missing Malaysia Airlines Flight MH370.

Everything is speculative until the debris is found, he told reporters, adding that no confirmed debris has been recovered yet.

A senior Australian air force officer said more assets are coming to refine the search for the jetliner, which mysteriously disappeared from radar on March 8 en route from Kuala Lumpur to Beijing.