Ukrainian President Volodymyr Zelenskyy hailed a "long-awaited victory" after a Dutch court ruled a collection of archaeological objects from Crimea should be returned to Kyiv.
The Ukrainian leader said on Tuesday that he was "grateful to the court for a fair decision."
"After the 'Scythian gold', we'll return Crimea," he added on Twitter.
Russia annexed Crimea in 2014, following a revolution in Ukraine that saw the former president and Russian ally Viktor Yanukovych ousted, and the government overthrown.
The annexation of the Crimean peninsula is viewed as illegal by most of the world, including the European Union.
Crimea had loaned the cultural objects to the Allard Pierson Museum in Amsterdam in 2014 shortly before the annexation of the peninsula by Moscow.
"The Amsterdam Court of Appeal ordered the Allard Pierson museum to hand over the 'Scythian gold' to the Ukrainian state", said the judges.
The ruling said that while the trove originates from Crimea and therefore “may be considered part of Crimean cultural heritage, they are part of the cultural heritage of the Ukrainian State” as it has existed since independence in 1991.
The court said in a statement that "the cultural interest that lies in preserving the museum pieces is a public interest of the Ukrainian State that carries great weight".
A lower court had already ruled in 2016 that the treasures should be handed to the Ukrainian government. But Tuesday's ruling can still be appealed to the Dutch Supreme Court
The collection is made up of 565 items, according to the Ukrainian Ministry of Justice, notably a solid gold Scythian helmet from the 4th century BC and a golden neck ornament from the second century AD that weigh more than a kilogram each.
On Wednesday, Russia's foreign ministry spokeswoman Maria Zakharova said the court ruling set a "dangerous precedent".
Zakharova said in a statement that Russia would launch an investigation following the "regrettable" and "politically motivated" decision.
"The verdict ... creates an extremely dangerous precedent that undermines trust between museum communities in different countries and calls into question the future prospects of inter-museum cooperation between Russia and the Netherlands," she added.
"Until recently, we hoped that at least the cultural sphere would remain outside politics."
Russia's Ministry of Culture has also said the ruling violates international law, while Kremlin spokesperson Dmitry Peskov warned that such statements could have "negative consequences".