President: Viktor Yanukovych
Mr Yanukovych was declared the winner of the second round of voting in the 2010 presidential election, with a 3.48% lead over Prime Minister Yulia Tymoshenko.
His inauguration as president marked the climax of Viktor Yanukovych's political comeback. First, he overcame the disgrace of the 2004/05 presidential defeat and retained the leadership of the Party of the Regions, leading it back into power as prime minister in 2006-2007.
He narrowly lost the 2007 parliamentary elections, but benefited from discord between President Yushchenko and Mrs Tymoshenko and went on to capitalise on discontent over the government's failure to cope with the global economic crisis after 2008.
Born into a poor family in Donetsk Region, eastern Ukraine's industrial powerhouse, in 1950, Mr Yanukovych had a troubled childhood and was twice jailed for violent crimes in his youth. On release he went to work in the local transport industry, where he rose through the ranks of management under the patronage of cosmonaut and local Soviet MP Georgi Beregovoi.
He established a political power base in the Donetsk Region administration, becoming governor in 1997 and later head of the council. There he built close ties to local tycoon Rinat Akhmetov.
President Kuchma appointed him prime minister in 2002, and nominated him as presidential candidate for the governing coalition of political and business interests in 2004.
Mr Yanukovych has worked hard to distance himself from the scandals of the pre-2004 period and from accusations of being Russia's placeman. He says that his aim is to balance relations between Russia and the European Union, with EU integration as a "strategic aim".
However, his first two years in office have seen extensive concessions to Russia, such as extending the Russian lease on the Black Sea Fleet base in Crimea, and moves to restrict media freedom.
His government regularly earns criticism from the United States, European Union and international rights groups over the imprisonment of Mrs Tymoshenko and other opposition politicians and the alleged rigging of the 2012 parliamentary elections.
Prime minister (acting): Mykola Azarov
Mykola Azarov, an ethnic Russian born in Russia, is a close associate of President Yanukovych and succeeded him as head of the Party of Regions in 2010. After the government of Mr Yanukovych's chief rival, Yuliya Tymoshenko, fell in a vote of confidence in March 2010, Mr Azarov formed a coalition with the Communists and the centrist Lytvyn Bloc.
Mr Azarov was head of the tax administration in 1996-2002, and his term as finance minister during Mr Yanukovych's subsequent premiership oversaw dramatic economic growth.
He was briefly acting prime minister during the presidential election crisis of 2004-2005, and resumed the post of finance minister during the Yanukovych government of 2006-2007.
A mining specialist, Mr Azarov is a technocrat with neither a political base nor ambitions of his own. His poor command of Ukrainian is often highlighted by his opponents, who see him as a symbol of Mr Yanukovych's alleged pro-Russian orientation.
His two years in office since 2010 have seen Ukraine's economy stagnate. Mr Azarov has refused of cut expensive gas subsidies, which the IMF says are a block on any further loans. Negotiations with Russia on the price of gas have stalled, plans to diversify Ukraine's sources of imported fuel have gone nowhere, and political tensions with the European Union have prevented progress on a free-trade agreement.
Mr Azarov was elected to parliament in October 2012, along with a number of other ministers, and is required by law to resign his post before taking up his seat as MP. President Yanukovych accepted the resignation of the entire government in December, and reappointed it on an acting basis. The president could reappoint Mr Azarov, or else take the opportunity to form a new government better equipped to pull the country out of a looming recession.