Bali Nine: Andrew Chan, Myuran Sukumaran placed in Nusakambangan isolation cells ahead of execution

Australian drug smugglers Andrew Chan and Myuran Sukumaran have been placed in isolation cells in Central Java while they wait for news about the timing of their executions.

Chan and Sukumaran finished their journey to the port of Cilacap shortly before 9:00am (local time), after being taken out of Bali's Kerobokan prison in a police armoured vehicle before dawn on Wednesday morning.

Photographs released by AAP news agency appeared to show Chan, 31, and Sukumaran, 33, being manhandled onto a chartered plane at Bali's Denpasar airport.

The men were then taken off the plane in Java and driven to Cilacap, where they were put on a ferry for the short journey to the Nusakambangan island prison, where they are due to be executed.

Their transfer, in paramilitary vehicles with a helicopter overhead and elite guards, was a relative show of strength compared to a third prisoner they transferred — an Indonesian drug trafficker who came in a little van.

An announcement on the timing of the executions could be made within hours or days, but Indonesian attorney-general Muhammad Prasetyo is required to give them 72 hours' notice.

Mr Prasetyo told local reporters that several things were still being organised and his office was always checking on progress in the field.

The attorney-general said the process would be carried through properly and not rushed, and that was why no execution date had been set.

Mr Prasetyo said some of those on the list to be executed were yet to be moved to Nusakambangan.

Just minutes before the duo left their Bali prison, Chan's brother Michael turned up at the gates and attempted to be allowed inside, but he was denied access.

The pair's Australian lawyer, Peter Morrissey, said the legal team still had two avenues to pursue to keep Chan and Sukumaran alive.

"We have a legal option, and that's pursuing the appeal that we've got in place, and there's the diplomatic option, which is just to keep the conversation going between Australian diplomats and politicians and their counterparts in Indonesia," he said.

Prime Minister Tony Abbott said the Government was "revolted" by the prospect of the two men being killed and was continuing to press Indonesia for a stay of execution.

"I think right now millions of Australians are feeling sick in their guts at the prospect of execution for these two," he said.

"But I've got to say anger is not a very good basis on which to determine a nation's policy, and in the long run, anger is not a very good basis on which to determine your own conduct.

"So let's see how things develop, let's maintain our values, let's maintain our respect for human life as a nation and as a society, but let's remember that a good relationship with Indonesia is very important to this country.

"And whatever might happen in the next few days, the relationship with Indonesia must endure and over time it must grow stronger."

Indonesia's ambassador to Australia, Nadjib Kesoema, said the imminent execution of the duo is very sad, but Indonesia is fighting a chronic drug problem.

Mr Kesoema spoke at a business breakfast in Perth shortly after Sukumaran and Chan were moved from Bali, and said more than 1,500 Indonesians died every month because of drug abuse.

He said the imminent executions were a "very bad and very sad situation also for Indonesia".

The ambassador insisted Indonesians were not "trigger-happy" and said the country was having a robust national debate on capital punishment.

Foreign Affairs Minister Julie Bishop told Parliament she had spoken to the "devastated" families of both men, and said she would continue to plead the two men's case.

"We will continue to appeal to President Widodo's strength and his humanity to show mercy and forgiveness for these two Australian men who have undergone this remarkable rehabilitation," she told Parliament.

Indonesian president Joko Widodo has insisted he will not grant clemency to drug traffickers on death row.

Federal politicians have re-formed the Parliamentarians Against the Death Penalty Group, which was disbanded at the last election, in a show of support for the Bali Nine pair.

The group has organised a candlelight vigil for the two men at the forecourt of Parliament House in Canberra on Thursday morning.

Ms Bishop, Opposition foreign affairs spokeswoman Tanya Plibersek and Greens leader Christine Milne are expected to attend.