Nine prisoners, including two Australians, are set to be executed in Bali later today.
Australian foreign minister Julie Bishop said she had received a letter from her Indonesian counterpart on Monday advising her there would be no reprieve for Myuran Sukumaran and Andrew Chan.
"They gave no indication that (Indonesian) President (Joko) Widodo would change his mind and grant the clemency that we have sought," she said.
The pair are among nine mainly foreign prisoners scheduled to be killed by firing squad at around 6pm.
Four Nigerians, an Indonesian, a Brazilian and a Filipino have also been told they will soon face the firing squad.
Indonesia has harsh punishments for drug crimes and resumed executions in 2013 after a five-year gap.
Chan and Sukumaran - ringleaders of a group of Australian smugglers who became known as the Bali Nine - were arrested at the main airport on the holiday island in 2005 for trying to smuggle 8kg of heroin to Australia.
They both face being tied to wooden planks in a field and shot by a firing squad of 12 police officers aiming at the heart.
They will be given the signal to fire by a commander dropping a sword.
However, only three of the squad will fire live rounds, so as not to identify the executioners.
According to the execution procedure, which is laid down in Indonesian law, if the first round of bullets does not kill them, they will be shot in the head.
Medical staff will then pronounce death before their bodies are handed over to their families.
Amnesty International is calling for an immediate and urgent halt to the plans.
"If these executions go ahead, they'll be a serious stain on Indonesia's human rights record and Joko Widodo's Presidency and damage relations between Indonesia and its friends, including Australia," said Diana Sayed, human rights lawyer and Amnesty International Australia crisis campaigner.
"Hundreds of thousands of people from right around Australia and the world have continued to respectfully call for a halt to the executions and mercy for those on death row."
