Lawmakers in the embattled Ukrainian region of Crimea have voted to join Russia, in a move likely to further escalate tensions.
Thursday's vote by the Moscow-backed Crimean parliament comes as European Union leaders gather for an emergency summit in Brussels to discuss how to pressure Russia to back down from its military incursion into Crimea. U.S. lawmakers are also meeting Thursday to discuss potential economic sanctions against Russia.
The government of Crimea, a Black Sea peninsula with a majority Russian population, said Thursday it is scheduling a referendum on joining Russia for March 16. Russian President Vladimir Putin is being asked to consider the appeal.
The Reuters news agency quotes Ukraine's economy minister as saying the referendum on Crimea's status is "unconstitutional."
Crimea's move to leave Ukraine is likely to shake up efforts toward a diplomatic resolution to the crisis.
EU leaders are considering possible sanctions against Russia at their meeting Thursday, but with Europe heavily dependent on Russian gas, it is unclear whether any measures adopted will be more than symbolic.
Ukrainian Prime Minister Arseniy Yatsenyuk is also attending the meeting. The gathering comes after the 28-nation EU offered Ukraine some $15 billion in aid to span the next couple years.
Meanwhile, direct efforts to end the crisis continue, with U.S. Secretary of State John Kerry scheduled to meet again with Russian Foreign Minister Sergei Lavrov in Rome Thursday.
Kerry held a series of discussions Wednesday with Lavrov, British Foreign Secretary William Hague and Ukrainian interim Foreign Minister Andriy Deshchytsia. The Russian and Ukrainian ministers did not meet face-to-face during Wednesday's flurry of negotiations, and Kerry said he had not expected they would.
Ukraine's crisis began when protests erupted in late November after then-President Viktor Yanukovych rejected a deal with the EU in favor of closer ties with Russia. What began as peaceful demonstrations eventually turned deadly as protesters clashed with police. Mr. Yanukovych fled the country last month.
As the U.S. and EU display their support for Ukraine's new government, the EU is punishing the nation's former leaders, freezing the assets of 18 high-ranking officials of the old government, including ousted President Yanukovych.
The EU announced the names of those targeted by the measures early Thursday, accusing them of embezzling state funds.
Mr. Yanukovych's son, his former justice minister and several other government ministers are also among those whose assets have been frozen.
Tensions in Crimea remain high, just days after Russian forces moved into the peninsula. Robert Serry, the United Nations special envoy to Crimea, was forced to cut his visit to the region short when he was confronted by a group of unidentified gunmen.
Concerns the turmoil could spread beyond Crimea remained heightened Thursday, amid clashes between pro-Russian demonstrators and Ukrainian police in the eastern Ukrainian city of Donetsk. Police took back a government building that had been seized Wednesday by demonstrators. Dozens of people were detained.
Western leaders have suggested the crisis in Crimea could be resolved if Moscow pulls back its forces to their bases on the Black Sea and allows in international monitors.
But Lavrov said Wednesday Russia cannot order pro-Russian armed forces in Crimea, which he described as "self-defense" forces, back to bases, because they are not Russian forces. He said allowing international monitors into Crimea is not Russia's decision, but the decision of Ukrainian and Crimean authorities.