A demonstration of two military planes taking off and landing on a toll road was held on the western island of Sumatra on Wednesday.

The roads would provide an alternative in the event military bases are attacked, deputy defence minister Donny Ermawan Taufanto said.

He described the test as a "good milestone", adding that a plan for building roads that double-up as runways was already in place.

At least one toll road in each of the country's 38 provinces is hoped to serve as a makeshift runway for military aircraft, said air force chief of staff Mohamad Tonny Harjono.

"I want to emphasise that the use of toll roads as an alternate runway for fighter jets is temporary and situational," he said.

"This means it will not be used continuously. We will use it only when necessary."

He did not specify a timeline for implementing the strategy, which has also been tested in other parts of the world.

Under President Prabowo Subianto, Indonesia is seeking to rejuvenate its ageing military equipment.

The archipelago of more than 17,000 islands received last month its first three French-made Rafale fighter jets as part of an $8.1 billion deal to purchase 42 jets from France.