Ukraine accused Russia on Tuesday of acting like an imperial power as it urged a tribunal in The Hague to take on its case over the seas around Crimea.

Kiev told the Permanent Court of Arbitration (PCA) that Russia had illegally blocked access to the Black Sea, Sea of Azov and Kerch Strait since annexing Crimea in 2014.

Russia had pressed the court during its opening arguments on Monday to throw out the case.

"Russia's approach is based on the imperial historical narrative pushed by its leaders. In the version of reality presented yesterday by Russia, nothing has changed since the Russian empire," Ukraine's deputy foreign minister Olena Zerkal told the PCA.

"This explains why Russia believes that it alone can make the rules, but it can't."

Zerkal criticised what she called Russia's "complete disrespect for the international law of the sea."

"Russia built an illegal bridge across an international strait, it harasses ships of all countries as they navigate to and from Ukrainian ports, it steals our energy resources from within our maritime areas, it excludes our fishermen from the waters they have always fished," she added.

Since its 2014 annexation of Crimea, Russia has controlled the Kerch Strait, the only way to pass from the Black Sea into the Sea of Azov, which is shared by both countries.

Ukraine filed a case with the PCA -- the world's oldest arbitration tribunal -- in 2016.

Russian President Vladimir Putin personally opened a bridge across the strait in May 2018, infuriating the EU and NATO and outraging Ukraine, which says its larger ships are unable to get under it.

In November, Russia fired on and seized three Ukrainian navy vessels, capturing dozens of sailors near the Kerch Strait as they tried to pass from the Black Sea to the Azov Sea.

The incident was the first open military clash between Kiev and Moscow since 2014.