Russia's nuclear-powered icebreaker Arktika, touted as the most powerful of its kind and a symbol of Moscow's Arctic ambitions, set off on its maiden voyage on Tuesday.
Designed to transport liquefied natural gas from the Arctic, the giant vessel is 173 metres long and 15 metres high.
"The unique domestically-built vessel will for the first time find itself in the extreme conditions of Arctic ice where it will have to confirm its status as the flagship of Russia's icebreaker fleet," said its constructors, the Baltic Shipyard in Saint Petersburg.
The Arktika is expected to arrive at its future home port of Murmansk in northwestern Russia in two weeks after undergoing tests of its performance en route.
Launched in 2016, it is part of a planned fleet of nuclear icebreakers aimed at significantly boosting freight traffic along Russia's Arctic coast, making the passage between the Pacific and Atlantic Oceans navigable all year round.
According to its constructors, the Arktika can cut through ice that is 2.8 metres thick.
Economic development of the Arctic is one of President Vladimir Putin's key goals.
The Arctic holds huge oil and gas reserves that are being eyed by Russia and other countries including the United States, Canada and Norway.