KIEV (CNN) — Russian Foreign Minister Sergey Lavrov told Russia's national legislature, the Duma, on Thursday that -- speaking "on behalf of" President Vladimir Putin -- he suggests lawmakers ratify an agreement to fold Crimea into Russia. "I hope this will become a turning point in the fate of many people who are united by many things," said Lavrov.
[Previous story, 8:16 a.m.]
Kiev will never stop fighting for Crimea, Ukraine's parliament said Thursday as European Union leaders prepared to hold critical talks on how to respond to Russia's annexation of the Black Sea peninsula.
The declaration came even though Kiev's new leaders said they were prepared to evacuate military personnel from the region if the United Nations designates Crimea "a demilitarized zone."
In an announcement that comes days after Moscow claimed the autonomous region as its own, the Kiev parliament said "Crimea was, is and will be part of Ukraine."
"The Ukrainian people will never, under no circumstances, stop fighting for the liberation of Crimea from the occupants, no matter how hard and long it is."
Russian President Vladimir Putin announced the annexation of Crimea after voters in the semi-autonomous territory approved a hastily called weekend referendum on separating from Ukraine.
Western leaders have denounced Moscow's actions as a violation of Ukraine's sovereignty and a breach of international law.
U.S. and EU officials have imposed sanctions on more than two dozen Russian and Crimean officials, and urged Russia to avoid escalating the crisis. Moscow has ignored those calls.
European Union leaders are due to meet in Brussels, Belgium, on Thursday to discuss the crisis, with possible further targeted sanctions.
Navy chief released
Ukraine's navy commander, detained when supporters of Russia took over the naval headquarters in Crimea, was released, the presidential website said Thursday.
Amid signs the uneasy standoff between pro-Russian and Ukrainian forces could ignite into bloody conflict, about 300 armed men stormed the naval base in Sevastopol on Wednesday. They took away Ukrainian navy chief Sergey Gaiduk.
Acting Ukrainian President Oleksandr Turchynov issued a 9 p.m. (3 p.m. ET) deadline for Crimea to release all hostages and stop all provocations. Kiev's new leaders had warned that if all hostages, including Gaiduk, were not released by then, authorities would take action of "technical and technological character," probably meaning turning off utilities.
A statement on the presidential site said Gaiduk and several other hostages had been freed. They were released during the night and on their way to Kiev.
Russian Defense Minister Sergey Shoigu had asked authorities in Crimea to free Gaiduk and allow him safe passage out of the region.
The incident at the navy headquarters comes a day after one member of the Ukrainian military was killed, another wounded and more captured when masked gunmen seized their base near the Crimean regional capital, Simferopol.
After that fatality -- the first Ukrainian military death since the Crimean crisis erupted about three weeks ago -- Ukraine's Defense Ministry authorized its forces to open fire in self-defense.
No hurry on visas
In Kiev, officials unveiled new measures against Russia and the "self-proclaimed" authorities in Crimea.
In a televised briefing, Andriy Porubiy, secretary of the national defense and security council, said that if the United Nations designates Crimea a "demilitarized zone," Ukraine was prepared to evacuate its military personnel and family members. Ukraine has facilities ready to accommodate 25,000 evacuees.
A separate statement on the Ukrainian presidential website said former Presidents Leonid Kravchuk and Leonid Kuchma had asked Turchynov to redeploy soldiers who are still in Crimea to the mainland.
The call was "to protect and save lives of Ukrainian servicemen who bear service in difficult and dangerous conditions in Crimea," the statement said. It said Kravchuk and Kuchma strictly condemned provocations and separatist attempts "in some regions" of the Eastern European country.
Porubiy had also said the measures included a full-scale visa system for Russians.
Speaking in Brussels on Thursday, Prime Minister Arseniy Yatsenyuk said Kiev was in no hurry to impose a visa regime on Russia.
"Such an initiative by Ukraine is most unlikely to be effective in terms of influencing Russia," he said, adding that the measure could negatively affect Ukrainians living in the predominantly Russian-speaking east of the country.
Yatsenyuk is in Brussels to sign the political part of an association agreement with the European Union.
As diplomatic efforts to resolve the crisis continue, U.N Secretary-General Ban Ki-moon will visit Russia and Ukraine this week. He will meet Putin and Russian Foreign Minister Sergey Lavrov in Moscow on Thursday and Ukraine's Turchynov and Yatsenyuk on Friday in Kiev.
Russian lawmakers closer to Crimea vote
Russia's Constitutional Court unanimously ruled Wednesday that the agreement between the Russian Federation and Crimea on its accession to Russia was lawful.
The step clears the way for the country's lawmakers to vote on ratifying the accession agreement, as well as draft amendments to the Russian Constitution, state news agency RIA Novosti reported.
The State Duma, or lower house, will hold a special session Thursday to ratify the treaty.
Lavrov said the legal process of bringing Crimea into Russia will be completed soon, Ria Novosti reported.
"At the moment practical steps for the fulfillment of the contract, which was signed between leaders of the Russian Federation, Crimea and the city of Sevastopol to bring two new subjects in Russia, have been taken. The legal process will be completed this week," he said.
Journalist Victoria Butenko reported from Kiev, CNN's Marie-Louise Gumuchian from London. CNN's Boriana Milanova contributed to this report.