UN human rights officials have expressed concern over the planned executions, urging Jakarta to put an end to "unjust" capital punishment.
The inmates have not been officially named but they are known to include citizens of Nigeria, Zimbabwe, Pakistan and India.
They will be executed at Nusakambangan prison island.
The prisoners have been notified of the plans for their executions, in accordance with Indonesian law, and could be put to death as early as Friday.
Attorney General Muhammad Prasetyo said the 14 had been put in isolation. The executions are due to take place by Sunday at the latest.
Zeid Ra'ad al-Hussein, the UN High Commissioner for Human Rights, expressed concern that the inmates had not received a fair trial, and urged Indonesia to halt the executions.
"The increasing use of the death penalty in Indonesia is terribly worrying and I urge the government to immediately end this practice which is unjust and incompatible with human rights," he said in a statement.
"The death penalty is not an effective deterrent relative to other forms of punishment nor does it protect people from drug abuse."
Mr Hussein called for the country to reinstate a moratorium on the death penalty it lifted three years ago.
Family members visited the prisoners on Wednesday at Nusakambangan, where Indonesia carries out executions.
Indonesia has some of the world's toughest drug laws and executed 14 drug convicts - mostly foreigners - last year, to widespread international condemnation.
Human rights groups and lawyers have lobbied President Joko Widodo to grant the prisoners clemency, but the hardline leader received similar petitions last year and denied them.
If the 14 executions go ahead this weekend, Mr Widodo will have put more people to death in two years than were executed in the previous decade.
Indonesia has confirmed it will execute 14 people on death row for drug crimes in the coming days.