He also sent condolence message to the families of the two victims expressing his deep regret over the loss.
Government spokesman Col Virachon Sukontapatipak disclosed Saturday that Prime Minister Prayuth sent the condolence message to Prime Minister David Cameron late Friday evening expressing profound regret and sadness of the deaths of Hannah Witheridge and David Miller.
In the message, Gen Prayuth assured the British premier that his government would pursue the case to bring the culprits to justice as soon as possible.
Besides he also pledged to take care of all foreign tourists visiting Thailand as best as Thai tourists, the spokesman said.
He also said relatives of the two victims would be given full convenience should they return to Thailand to follow up the case.