Ukrainian President Volodymyr Zelenskyy opened an international conference on Crimea on Tuesday by saying Kyiv would restore Ukrainian rule over the region.

At the Crimea Platform conference in Kyiv, French President Emmanuel Macron vowed that the EU's support for Ukraine would continue "for the long term."

"Our determination has not changed, and we are ready to maintain this effort for the long term," Macron said in a video address.

NATO Secretary General Jens Stoltenberg urged allies to sustain their support for Kyiv at the conference, saying the alliance will stand with Ukraine for as long as it takes.