Nineteen-year-old Australians Bianca Jones and Holly Bowles died in Thai hospitals on Thursday and Friday, respectively, of suspected methanol poisoning after drinking tainted alcohol in Laos.
The teenagers had been evacuated from Laos to Thailand for emergency treatment.
Both were found sick in their room at the Nana Backpacker Hostel on November 13 after they failed to check out as planned.
The UK Foreign Office named 28-year-old British woman Simone White as another of the victims.
An American man and two Danes also died, although their exact causes of death have not been released.
A New Zealander has also fallen ill.
In a short statement released to the media on Saturday, the Laotian government said it was "profoundly saddened over the loss of lives of foreign tourists" in the town of Vang Vieng and offered its condolences to the families of the victims.
"The government of the Lao PDR has been conducting investigations to find causes of the incident and to bring the perpetrators to justice in accordance with the law," it said.
