MOSCOW -- President Mikhail S. Gorbachev warned the Russian government of Boris N. Yeltsin yesterday against overstepping its bounds, as the issue of Russia's mushrooming power within what's left of the Soviet Union leaped to the fore.
Mr. Gorbachev, who several days ago appeared to be acting virtually at Mr. Yeltsin's bidding, asserted his government's authority yesterday.
"Everything must be based on the constitution," he said.
As if to demonstrate his command, Mr. Gorbachev dismissed the entire Collegium, or executive board, of the KGB, and effectively dismantled the secret police department as an instrument of the Communist Party's historic repression and fear.
He also appointed his own foreign minister, Boris Pankin, after accepting a string of Yeltsin men for key government positions in the days following the short-lived coup.
But Mr. Gorbachev's warning didn't stop Valentin Stepankov, the Russian prosecutor, from bringing treason charges against 13 men accused of plotting last week's coup.
They are the seven surviving members of the so-called State of Emergency Committee and six others -- including defense aides, Mr. Gorbachev's own former chief of staff and two high-ranking KGB officers.
Those convicted of treason could face the death sentence.
And Mr. Yeltsin -- who besides placing his allies in positions of power within the Soviet government has continued to issue decrees affecting the KGB and the Communist Party -- acted as though Russia was rightfully assuming its inherent powers.
"The disintegration of the central authorities is not the disintegration of the country, especially not of Russia," he told a Moscow gathering of Russians now living abroad.
"Mother Russia," Mr. Yeltsin said, would remain indivisible and strong.
As if to dramatize his approach, he said he was considering turning over the Kremlin cathedrals to the Orthodox Church. "The Kremlin belongs to Russia, not to the center," he declared.
On one issue Mr. Yeltsin did relent late yesterday. Tuesday he had issued a decree placing all foreign exchange transactions under Russian control, but yesterday authority over those transactions was handed back to the Soviet Bank for Foreign Economic Affairs.
Mr. Yeltsin's decree had run into strong criticism from foreign bankers who question his understanding of finance.
But the non-Russians in the Soviet Union are nevertheless growing increasingly uneasy about what they see as the Russian swagger.
On Monday, Mr. Yeltsin said he thought Russia's borders with neighboring republics should be open to negotiation -- so that Russia could expand to include ethnic Russian enclaves in the Ukraine and Kazakhstan.
That remark brought forth immediate criticism, especially in the Ukraine, which declared its independence Saturday.
Two delegations -- one Russian and one Soviet -- flew to Kiev, the republic's capital, yesterday, to try to persuade the Ukrainians to stay in the union and to smooth over the bitterness caused by Mr. Yeltsin's comment.
Angry Ukrainian demonstrators met them in Kiev, however, chanting, "No to the imperial center."
Col. Vilen Martirosyan, a Ukrainian deputy to the Supreme Soviet,told the Interfax news agency in Moscow that the delegations were "trying in vain to stir up public opinion."
The Ukrainians in Kiev made it clear that they were not interested in overthrowing the Communist Party and Soviet government only to have a new Russian government step in to give them orders.
The Ukraine is the second-largest Soviet republic, with 50 million people, and a vital center of industry and agriculture.
Without the Ukraine, there is little chance that the Soviet Union could hold together.
On a related issue, Mr. Yeltsin proposed yesterday that all nuclear arms be stationed on Russian soil to keep them in the hands of a stable government.
Currently, he said, 15 percent are in the Ukraine, Byelorussia or Kazakhstan.
The Ukrainian representative to the United Nations said yesterday that if the Ukraine becomes independent, following a referendum in December, it will declare itself a nuclear-free zone.
The issue of who controls the Soviet arsenal and military -- Mr. Yeltsin or Mr. Gorbachev -- could become crucial.
During the three days that the junta was in power, Mr. Yeltsin declared himself commander in chief of the military.
Yesterday, Mr. Gorbachev said that decree and others had been proper under the circumstances, but he emphasized that authority must now revert to the central government.
Mr. Yeltsin, though, is the unchallenged hero of the democratic resistance to the junta, a feat for which Mr. Gorbachev himself lavished praise on the Russian president. He is enormously popular, and Mr. Gorbachev, who many believe brought the coup upon himself through poor and ineffectual decisions, is not.
In the days following the restoration of a somewhat baffled-looking Mr. Gorbachev, Mr. Yeltsin helped himself to enormous gobs of power.
Now, Mr. Gorbachev seems to be regaining his balance.