The war in Ukraine began with Crimea and must end with its liberation, President Volodymyr Zelensky has said.
He was speaking just hours after a string of explosions hit a Russian airbase there, killing one person.
Mr Zelensky did not mention the blasts but devoted his nightly address to the peninsula, saying: "Crimea is Ukrainian and we will never give it up."
Russia has played down the explosions, and a top Ukrainian adviser denied Ukraine was responsible.
Crimea is officially part of Ukraine but was annexed by Russia in 2014 after a referendum which the international community sees as illegitimate. Many Ukrainians see this as the start of their war with Russia.
On Tuesday, a series of explosions rocked the Saky military base near Novofedorivka, in the west of Crimea - which is near seaside resorts popular with Russian tourists.
Russia's defence ministry insisted the blasts were down to ammunition that had exploded in a store - although this has not been independently verified, reports BBC.
And Ukrainian presidential aide Mykhailo Podolyak denied that Ukraine was behind the blasts, telling the Dozhd online television channel: "Of course not. What do we have to do with this?"
Any attack on Crimea by Ukraine would be considered deeply serious by Moscow. Russia sounded a warning last month when ex-President Dmitry Medvedev threatened that "Judgement Day will instantly await" if Ukraine targeted Crimea.
Mr Zelensky did not refer to the blasts in his speech on Tuesday, but spoke at length about the peninsula, saying: "We will not forget that the Russian war against Ukraine began with the occupation of Crimea.
"This Russian war...began with Crimea and must end with Crimea - with its liberation," he said.
Mr Zelensky's latest remarks suggest he believes that Ukraine must retake the peninsula before the war can end - but in the past he has said different things on the issue.
He previously indicated Ukraine could accept peace if Russia returned to their positions before 24 February, meaning retaking Crimea would not be considered a requirement.
