MIKHAIL GORBACHEV, the father of perestroika, was ousted as president yesterday before he could lay the foundation for a new Soviet Union that would forever alter the national power structure.A state of emergency has been imposed in key areas of the Soviet Union, including Moscow and Leningrad, for the next six months, according to the official news agency Tass. Elite troops occupied key government facilities in Moscow, including the television center, early yesterday. Armored personnel carriers rumbled through the capital's streets, and tanks surrounded the parliament building of the Russian Federation and the Kremlin. A major confrontation was brewing with angry citizens squaring off against a column of tanks. At the parliament building people built barricades and blocked streets with trucks and busses, stopping the tank column. Then they implored troops in the tanks not to fire on citizens. The new political leadership is a so-called State of Emergency Committee, comprising hard-liners such as acting President Gennady Yanayev, KGB chief Vladimir Kryuchkov, Interior Minister Boris Pugo, Defense Minister Dmitri Yazov and Prime Minister Valentin Pavlov. Officials in the Russian Federation, the largest and most powerful of the 15 Soviet republics, quickly denounced the hard-liners' action as "unconstitutional and unlawful" and called for Mr. Gorbachev's restoration. "This is a state coup," Russian Prime Minister Ivan Silayev said at a news conference. "The popular will should rise up against it." Russian President Boris Yeltsin, looking shaken but speaking calmly, called for a general strike to combat the coup. He issued an appeal for troops on Russian territory not to obey orders. He also vowed not to deviate from radical reforms in the republic. "No one can prevent me from fulfilling my role as the elected leader of... Russia," he said. According to Tass, Mr. Gorbachev resigned because of an inability "to perform his duties for health reasons as USSR president." The move came a day before the new Treaty of Union was to be signed by several republics, including Russia. The treaty would have altered the Soviet power structure drastically by granting decisionmaking powers to the republics. Apparently leading hard-liners both in the Communist Party and the government decided to stage a palace coup before their powers were diminished almost to the point of insignificance. A statement issued by Parliament Speaker Anatoly Lukyanov said the union treaty will be revised to preserve the unitary character of state institutions. Mr. Lukyanov expressed the anger undoubtedly felt by many hard-liners, saying Gorbachev ignored the wishes of the conservative-dominated Supreme Soviet, or parliament, as well as the results of a nationwide referendum in March that called for the preservation of a renewed Union of Soviet Socialist Republics. The new union treaty would have transformed th e nation into the Union of Soviet Sovereign Republics. For the last few weeks Gorbachev has been on vacation in the Crimea, but he was to have returned to Moscow for the treaty signing ceremony. Mr. Yeltsin said his attempts to reach Gorbachev were unsuccessful. Shortly after Gorbachev's resignation was announced, acting President Yanayev sought to ease foreign leaders' concerns. "The measures that are being adopted today are temporary," he said. "They in no way mean the renunciation of the course towards profound reforms in all spheres of life." At the same time, the committee indicated it would not pursue as close a relationship with the West as Gorbachev had built. "Only irresponsible people can bank on aid from abroad. No handouts can solve our problems, our rescue is in our own hands," the committee said. Though the State of Emergency Committee said it isn't turning its back completely on perestroika, it made it clear that drastic changes were in order. "The policy of reforms, launched at Mikhail S. Gorbachev's initiative and designed as a means to ensure the country's dynamic development and the democratization of social life has entered, for several reasons, a blind alley," the committee said. "The country has, in fact, become ungovernable," the statement continued, alluding to the interethnic conflicts raging in the Soviet Union. Among the first acts by the committee was the cancellation of the highly unpopular five percent sales tax that Gorbachev introduced earlier this year. Hard-to-get goods, such as coffee, also have appeared in stores. The committee also banned all political activity and threatened to dissolve any republican parliament that does not adhere to the national constitution as interpreted by the committee. In addition, paratroopers occupied media facilities belonging to reform-minded organizations and government bodies, including Vesti, Russia's official television news. Soviet forces on land and sea acted today to seize key sites in the secessionist Baltic republics, officials and witnesses said. Warships blockaded the harbor in the Estonian capital, Tallinn, and the Latvian Foreign Ministry said the city of Liepaja, site of a major Soviet naval base, had been taken over by the Soviet military. In Lithuania, President Vytautas Landsbergis appealed to the world to support his republic against "the danger of Soviet military intervention."