Momock Bambang Samiarso, Bali's chief prosecutor and the man in charge of the transfer, made the announcement after meeting with police, military and other officials.

The transfer will use two military transport planes, he said. One will contain the Australians and their guards. The other will contain another contingent of security personnel.

He said the transfer would occur on Wednesday "siang", or day. The phrase usually denotes a time between 10am and 3pm, but sources said the men would be removed from Kerobokan prison at close to noon.

The men are expected to be transported to Denpasar airport from the prison in armoured personnel vans, most likely the police's Barracuda vehicles. 

The reformed drug smugglers can expect to be executed soon after the transfer, with Indonesia's attorney-general saying that the execution by firing squad of the two men and eight other drug felons will happen "ASAP".

The men will be given 72 hours notice before they are killed. They will be able to see their families, lawyers and a religious counsellor while on Nusakambangan, an island with a prison complex in Central Java.

The transfer will occur before the lawyers for the duo will be able to lodge an appeal against the refusal of Indonesian president Joko Widodo to grant clemency to the men, part of a blanket rejection of all 64 drug offenders on death row. Six of them have already been killed in January.

Indonesia's attorney general Prasetyo said on Monday that legal appeals pending for Chan and Sukumaran would not have any impact on the executions. Because the drug smuggling duo had their clemency appeals rejected by Indonesian President Joko Widodo, he said, these later appeals were irrelevant.

Lawyers for Chan and Sukumaran reacted angrily to the remarks, saying Mr Prasetyo was not respecting the rule of law in the country and would bring international condemnation upon Indonesia by rushing through the executions.

Mr Prasetyo revealed on Tuesday that prisons on Nusakambangan have requested that the Bali nine duo not spend too much time in isolation on the island.

Stating - as he did on Monday - that preparations were 95 per cent complete for the execution of 10 drug felons, Mr Prasetyo said an evaluation of the first batch of executions this year had shown there were things that needed to be improved.

The execution of six drug felons on January 18 was hampered by weather problems, journalists masquerading as fishermen to try and access the island and confusion over the religion of those condemned.

"We will immediately carry out the executions when the preparation is completed,"  Mr Prasetyo said on Tuesday. "The principle is that once they are there they should not wait too long in their cell."

There were also still prisoners who needed to be transported from Madiun and Yogyakarta. "After the evacuation we will determine the time of the execution," Mr Prasetyo said. He confirmed that Chan and Sukumaran would be transferred to Cilacap, the port near Nusakambangan, by plane.

Indonesia plans to kill 10 drug felons in a mass execution that will require 120 members of a combined firing squad, 12 for each victim.