INDONESIA has beefed up its military presence in waters off its southern border as military officials claim its air force is ready and that Australia is "reachabale" if there are any more border violations.

Indonesian military officials have today told the Jakarta Post its Navy warships, including frigates, fast torpedo craft and corvettes as well as maritime patrol aircraft, have been deployed to waters off its southern border.

Four Air Force defence radars have also been programmed to closely monitor the area.

"We are watching four radars in Timika, Merauke (in Papua), Saumlaki (Maluku) and Buraen (East Nusa Tenggara), which all face Australia," Air Force chief spokesman Air Commodore Hadi Tjahjanto told The Jakarta Post.

"If we notice any border violations, our air base in Makassar will be ready. Australia is reachable from there."

The Post said the base referred to was the Sultan Hasanuddin Air Force Base in the South Sulawesi provincial capital, home the 11th squadron of 16 Russian-made Sukhoi Su-27/30 Flankers.

The newspaper said the flankers have a maximum range of some 3,000 kilometers. The sea border lies some 1,000 km from Makassar. At Mach 1, or the speed of sound, the Flankers would reach the border in little over an hour.

Comment is being sought from Prime Minister Tony Abbott's office and the Australian Defence Force.

The developments come after Australia admitted last week it had accidentally breached Indonesia's sovereignty during asylum seeker missions in recent weeks.

Professor Damien Kingsbury from Deakin University told News.com.au: "Indonesia has always been pensive about its territorial integrity and Australia has played a role in that in the past."

"There's a sensitivity about that. If Indonesia did that to Australia we'd be very upset, if not more so," he said.

The Australian Government apologised to Indonesia after Navy vessels "inadvertently" breached Indonesia's territory "on several occasions" in recent weeks.

Australia's relationship with Indonesia has hit rocky waters recently, particularly because of the government's 'turn back the boats' policy and allegations from US intelligence whistleblower Edward Snowden that Australia spied on the country's president, Susilo Bambang Yudhoyono, and his wife, Ani in 2009.

Professor Clive Williams, from Australian National University's Centre of Military and Security Law, hosed down concerns, saying it was just rhetoric that was good for Indonesia's politicians ahead of looming elections.

But he said Australia had blundered last week by admitting the sovereignty violations, which then demanded a response.

"It's probably good mileage for politicians in Indonesian to be extra nationalistic," he said.

"I would doubt whether they would follow through on that - it's very much for home consumption. The stupidity on our part was admitting we'd entered their waters. That was unnecessary on our part and has just created problems."