Mr Abbott made the remarks after he spoke to the Indonesian leader on Wednesday evening.

The conversation came as Indonesian authorities revealed plans to execute 10 drug felons simultaneously, a mass execution that would require a combined firing squad of 120 people.

Chan and Sukumaran are among those 10 slated to be executed but Mr Abbott said it was a "positive sign" that the Indonesian leader had taken his call, although he cautioned against any undue optimism.

"The President absolutely understands our position ... and I think he is carefully considering Indonesia's position," he told reporters at Old Parliament House in Canberra.

Mr Abbott said he did not want to "raise hopes that might turn out to be dashed" and described the President as a "friend".

The Australian government has been agitating for months for Indonesia to show clemency to the duo. Most of Mr Abbott's entreaties, until now, have been relayed by letter.

His telephone conversation follows similar calls that the Indonesian president has received from the leaders of France, Brazil and the Netherlands. Nationals from each country has either been executed, or are scheduled to face a firing squad.

Despite the mounting international pressure, Mr Joko has remained implacable in his push to kill drug traffickers and has prioritised foreigners to be executed first.

He says the executions are a matter of Indonesia's legal sovereignty and an important response to a "drugs emergency" being faced by the country.

The diplomatic manoeuvres come as chilling details emerged of plans for the Bali nine duo to be shot simultaneously in a field with eight other drug offenders.

"It will be done simultaneously with all 10 convicts," Tony Spontana, the spokesman for the Indonesian attorney general, told Fairfax Media.

He denied media reports that the location had been decided, saying several alternatives were being reviewed.

Each execution victim is killed by a team of 12 specially trained police officers. Only three in each squad have live bullets.

Authorities also said that isolation cells will be ready on Saturday on Nusakambangan, the penal island where the executions will take place.

Lawyers for Chan and Sukumaran are preparing a further legal appeal to overturn Mr Joko's refusal to grant clemency to the pair.

No date has been set for the executions but, in the seaport town of Cilacap, which is divided from Nusakambangan by a narrow strait, people are on standby.

The local priest believes at least three of the 10 condemned prisoners are Catholics, and is waiting to be asked to perform the last rites.

The doctor at the government health office wondered if his ambulance will be called upon, as it was when three murderers were executed in 2013.

The undertaker, Suhendro Putro, has stocked up on an extra six coffins. He was warned by police to have sufficient this time after he was caught short when five drug felons were killed on the island on January 18.

He can usually only accommodate nine coffins, but he now has 12, including one jumbo size and two for children.

Despite ghoulish speculation in the media that the large coffin has been earmarked for Sukumaran, who is nicknamed "the gentle giant", Mr Suhendro said it had been in stock for three months.