Ukraine's parliament has voted to dismiss President Viktor Yanukovych and called for early presidential elections on May 25, but the embattled leader says he will not resign or leave Ukraine.
Parliament on Saturday also voted to free jailed opposition leader Yulia Tymoshenko, a former Ukrainian prime minister. She was later released from a prison hospital in the northeastern city of Kharkiv where she was serving time for abuse of power.
Ms. Tymoshenko, a long-time adversary of Mr. Yanukovych, said after her release that the "dictatorship has fallen."
She later delivered a fiery speech to thousands of supporters in Kyiv's Independence Square, the epicenter of Ukraine's protest movement. She told the crowd, "You are heroes, you are the best of Ukraine," before breaking down in tears.
She also honored the protesters who have lost their lives.
In an interview Saturday with a Ukrainian television station, Mr. Yanukovych said he intends to remain in office. He called the violent uprising against him an example of a "coup," and compared it to the Nazis' rise to power in Germany in the 1930s.
The president, who is in Kharkiv near the Russian border, also said all decisions made by Ukraine's parliament Saturday were illegal.
The United States welcomed the latest developments in Ukraine and urged the quick formation of a unity government. In a statement, the White House said the developments could move Ukraine closer to a descalation of violence, constitutional change and early elections.
The White House also welcomed the release of Ms. Tymoshenko.
On Saturday, Ukrainian protesters took control of President Yanukovych's offices in Kyiv. Thousands massed in Independence Square, calling for the president's resignation.
Demonstrators also objected to a deal signed Friday by Ukraine's president and the opposition aimed at ending the country's political crisis.
The deal returns Ukraine to its 2004 constitution, limiting presidential powers. It also sets up a coalition government and early elections.
On Saturday, Russian Foreign Minister Sergei Lavrov told officials from France, Poland and Germany the opposition was failing to fulfill Friday's agreement. Foreign ministers from those three countries helped broker the deal.
Protests erupted in Ukraine in November when President Yanukovych backed out of a trade deal with the European Union in favor of closer ties to Russia. The protests began peacefully but descended into violence earlier this month. Nearly 100 people have been killed, including some protesters who were shot in the head by police snipers.
Also Saturday, opposition leader Vitaly Klitschko urged Mr. Yanukovych to resign so elections can be held no later than May.
On Saturday, parliament elected a new speaker, Oleksandr Turchynov, a longtime ally of Ms. Tymoshenko. Turchynov was elected soon after pro-government speaker Volodymyr Rybak submitted his resignation, citing ill health.
Ukraine is split between those in the east who favor ties with Russia, and those in the west who lean toward the European Union.