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.
Footage on social media showed beachgoers running as the explosions hit, with witnesses saying they had heard at least 12 blasts. Crimea's Russian-appointed health department said one civilian had been killed and another eight injured.