Four Portuguese friends, aged around 30, set out from their campsite towards Senj in a small inflatable boat shortly after 3am on Wednesday. Their boat sank in severe weather and they went missing in the Velebit Channel.
Two of the group were rescued alive, the ministry said, while expressing deep sorrow over the death of one Portuguese national and extending its condolences to his family and friends.
"Croatian authorities are continuing search and rescue operations to locate the last missing Portuguese national, in close contact with the Portuguese embassy and the Portuguese government," the Portuguese Foreign Ministry added.