Iran has announced its intent to establish a national cryptocurrency. Mohammad-Javad Azari Jahromi, head of Iran's Ministry of Information and Communications Technology, posted in a Tweet that a test model for a cloud-based digital currency is being developed. The announcement comes after Venezuela's oil-backed "petro" cryptocurrency launch earlier this week. Venezuelan President Nicolas Maduro claims that the cryptocurrency has raised over $700 million. There are fears that the rise of state-backed cryptocurrencies could challenge international efforts to regulate financial transactions and impose sanctions. The three countries most interested in the technology, Iran, Venezuela and Russia, are all targeted by U.S. sanctions.