No breakdown of the numbers of foreigners on death row have been given but citizens of France, Britain and the Philippines are among them
Indonesia will hold a round of executions on July 29 which will include a Pakistani prisoner, a Pakistani embassy official said on Tuesday.
Indonesian authorities are preparing to execute by firing squad at least three foreign prisoners, including citizens of Nigeria and Zimbabwe. They are among 16 prisoners who Indonesian officials have said are to be executed this year.
Authorities have not given a breakdown of the numbers of foreigners on death row but citizens of France, Britain and the Philippines are known to be among them.
It is unsure how many convicts will be executed this week, but local media reported at least 14 had been moved to an isolation cell on the high-security prison island of Nusakambangan, a routine practise ahead of executions.
This will be the third time execution carried out under Indonesian President Joko Widodo, who has declared a "drug emergency" in the country, and vowed to show no mercy for drug traffickers.
Last year, Indonesia executed 14 people, mostly foreign drug traffickers, prompting Australia and Brazil to briefly recall their ambassadors.
Indonesia imposed a moratorium on executions for five years before resuming them in 2013.