The couple presented with an illness while holidaying in the Western Division.
They were provided with medical treatment but their illnesses progressively worsened and despite best efforts, they died within a few days of each other.
At this stage the Ministry is conducting investigations into the possible causes and has also put in place necessary public health measures.
A US media report said the couple's family believe they might have contracted a virus.
The couple, who have a young son, were understood to be in the middle of round the world trip.
The Ministry is also working with the Fiji Police's forensics department, the World Health Organisation, and the United States Centres for Disease Control and Prevention, on determining the cause of death.