Ukrainian President Volodymyr Zelenskiy set up a reintegration council on Thursday to advise on the restoration of Ukrainian rule over Crimea, saying liberation of the peninsula, seized by Russia in 2014, will "happen for certain".
He was speaking at a gathering in Kyiv to mark the anniversary of the mass Soviet-era deportation of Crimean Tatars from the peninsula in 1944.
Zelenskiy said that more and more countries realised it would be impossible "to return peace to international relations and the full force of international law" without first returning Crimea.
"We continue our work in order to liberate the Crimea. It will happen for certain - its full-fledged return to Ukraine's state system," Zelenskiy told Tatar community leaders and senior officials.
"We are preparing to reintegrate Crimea. I signed the decree about the advisory council on reintegration and de-occupation of our Crimea and the (Crimean port) city of Sevastopol."
Russia shows no sign of abandoning Crimea, home to its Black Sea fleet, and has used the peninsula as a platform to launch missile strikes on Ukrainian targets.
Kyiv is planning to launch a counteroffensive against Russian forces and hopes it will change the dynamics of the war that has raged since Moscow invaded Ukraine in February last year. Ukrainian officials have repeatedly said that seizing the peninsula back from Russia is one of its key objectives.
Zelenskiy and other officials held a minute of silence to remember victims of the 1944 deportation of some 200,000 Crimean Tatars to Siberia and Central Asia under the orders of Soviet leader Josef Stalin.
Zelenskiy also said Ukraine was working hard to free Crimean Tatars who were being held in Russia.
Moscow has denied accusations of human rights abuses in Crimea, and says a referendum held after Russian forces seized the peninsula showed that Crimeans genuinely want to be part of Russia.
The referendum is not recognised by most countries.
(Reporting by Olena Harmash; Editing by Nick Macfie)