Crimea's regional assembly has declared independence from Ukraine and applied to join Russia, saying all Ukrainian state property on the peninsula would be nationalised.
"The republic of Crimea appeals to the United Nations and to all countries of the world to recognise it as an independent state," read a document approved on Monday by the assembly, a day after the region voted overwhelmingly to become part of Russia.
It followed the announcement by introducing the Russian ruble as a second currency alongside the Ukrainian hyyvnia.
Al Jazeera's Barnaby Philips, reporting from Simferopol, said Crimean officials would be travelling to Moscow on Monday afternoon, and that there were already plans to move to Russia's timezone.
Meanwhile in Kiev, Ukraine's parliament approved the partial mobilisation of troops to counter "Russian interference" in the country.
A majority of deputies approved the motion, citing "the worsening political situation in the country... and Russia's interference in Ukraine's internal affairs."
In response to Crimea's declaration of independence, European Union foreign ministers moved towards imposing more sanctions on Russia over its role in the breakaway.
The 28-nation EU condemned the Crimea referendum which overwhelmingly backed a return to Russia, and the EU ministers were expecting to have agreed a full list of individuals to target for asset freezes and travel bans by late Monday.
British Foreign Secretary William Hague, meanwhile, said he was confident that the EU would ratchet up pressure on Russia.
The head of the referendum commission in Ukraine's Crimea said the final results of the Sunday vote showed that 97 percent of voters had supported joining Russia.
Mikhail Malyshev said in a televised news conference that the final tally was 96.8 percent in favour of splitting from Ukraine.
The process to merge with Russia could take months and is mired in uncertainty for a region that remains heavily dependent on the Ukraine mainland, which supplies its water among other essentials.
There was sharp international condemnation of the vote, which could see the most radical redrawing of the map of Europe since Kosovo's 2008 declaration of independence from Serbia.
The European Union said the referendum was "illegal and illegitimate" and its outcome would not be recognised.
US President Barack Obama has told Russian President Vladimir Putin that Crimea's vote to secede from Ukraine and join Russia "would never be recognised" by the United States, as he and other top US officials warned Moscow against making further military moves towards southern and eastern Ukraine.
The White House said Obama reminded Putin over the phone that the US and its allies in Europe would impose sanctions against Russia should it annex Crimea.
Putin maintained that the vote was legal and consistent with the right of self-determination, according to the Kremlin.
In the call, Obama urged Putin to pursue a diplomatic de-escalation of the crisis, support the Ukraine government's plans for political reform, return its troops in Crimea to their bases, and halt advances into Ukrainian territory.
Obama told Putin that "a diplomatic resolution cannot be achieved while Russian military forces continue their incursions into Ukrainian territory and that the large-scale Russian military exercises on Ukraine's borders only exacerbate the tension," the White House said in a statement.
Russia, meanwhile, maintains the acting government in Kiev is illegitimate and says it seized power in a "coup".