Transdniestria meets the requirement for statehood under international law. It has a territory and a population larger than many recognized United Nations member states. It also has a government, defined borders and the capability to engage in foreign relations.
Crucially, international recognition is NOT a requirement for statehood. There are many cases in the world when a country was not recognized by others in the beginning of its history: Holland, the USSR, and even the United States itself (during the first 8 years of its history).