In an interview with AFP, Ryamizard Ryacudu said bolstering defences around Indonesia's Natuna Islands would involve deploying warships, an F-16 fighter jet, surface-to-air missiles, a radar and drones, as well as constructing new ports and improving an airstrip.
The military build-up, which started in recent months, would be completed in "less than a year", he said.
"This will be our eyes and ears," the retired general said.
His comments came after a UN-backed tribunal in The Hague ruled yesterday against China's expansive claims in the South China Sea, finding in favour of a challenge from the Philippines which has long-running territorial disputes with Beijing in the waters.
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The surprisingly strong ruling provided ammunition for Manila and other claimants locked in disputes over the resource-rich sea but sparked fury from Beijing, which warned its rivals against turning the waters into a "cradle of war" and threatened an air defence zone.
But Beijing's claims overlap Indonesia's exclusive economic zone -- waters where a state has the right to exploit resources -- around the Natunas, and there has been an upsurge in clashes between Indonesian patrol and navy boats and Chinese fishing vessels and coastguards.
The increase in high-seas confrontations has been triggered by Indonesian authorities' aggressive crackdown on illegal fishing in its vast waters.
After a clash last month, President Joko Widodo visited the Natunas on a warship with his cabinet to send a message to China that Jakarta is serious about defending the remote archipelago.