Russian President Vladimir Putin was due to open a 19-kilometer bridge connecting southern Russia to the Crimean peninsula on Tuesday.
The controversial Crimean Bridge links the southern Krasnodar region with the Crimean city of Kerch and spans across a stretch of water between the Black Sea and the Azov Sea.
The project cost 228 billion rubles ($3.69 billion, €3.1 billion) and will become the longest bridge in Europe, taking over the Vasco da Gama Bridge in Lisbon, Portugal.
It had been expected to be fully constructed by the end of 2018 but has been completed six months ahead of schedule and will be open to traffic on May 16, according to a Kremlin statement.