Boris Yeltsin called Monday for a referendum in his vast Russian republic on Mikhail Gorbachev's performance as president.

Yeltsin, president of the Russian Federation, largest of the 15 Soviet republics, said his region was ready to conduct such a referendum.Speaking in Kiev, where he was to sign a treaty with the Ukraine, Yeltsin said the referendum would also ask Russians whether they have confidence in the central government.

"Russia is ready to hold a referendum on two questions - the entire presidency of Mikhail Gorbachev and on faith in the central government," he told the Ukrainian parliament.

Such a plebiscite would ask more than half the Soviet Union's 290 million people to cast judgment on Gorbachev's performance, possibly laying the basis for a more direct challenge from Yeltsin.

Yeltsin censured Gorbachev's new plan, announced Saturday, to take charge of all government ministries as a bid to increase his personal power and a betrayal of promised decentralization.

Yeltsin compared Gorbachev's recent steps to the failed rule of the late Nikita Khrushchev, "when the center tried to recentralize everything, and the reforms died."

The burly Siberian also took issue with Gorbachev's recent decree requiring enterprises to give up most of their hard currency earning to the central government, calling it the "biggest mistake" of Gorbachev's eight-month presidency.

Yeltsin said the hard-currency order, if implemented, "will force us to our knees."

Though Gorbachev has led the country since March 1985, he assumed the new presidency last March after creating the office as a vehicle for moving his stalled reforms forward.

Yeltsin's call for a referendum was his latest salvo in his battle with Gorbachev on the best way to end the paralysis of power in which laws are disregarded across the broad land.

On Friday, Yeltsin called for a parliamentary vote of no-confidence in the central government, the resignation of Premier Nikolai Ryzhkov and the creation of an "anti-crisis committee" on which the leaders of the 15 republics would effectively run the country.

Yeltsin flew to Kiev on Sunday to sign a treaty between Russia and the Ukraine. The pact will outline the fundamental relations between the two most populous, industrially mighty and important republics in the Soviet Union.

Though largely symbolic, the accord furthers Yeltsin's policy of decentralization in which republics determine their own economic development and manage their natural resources.

The unannounced trip exemplified the politics of surprise that has elevated Yeltsin to his role as chief irritant and main rival of Gorbachev.