President Mikhail S. Gorbachev said Wednesday he will not hesitate to impose emergency rule in republics where ethnic and political conflicts threaten lives.

Gorbachev's forceful speech to the Congress of People's Deputies at the Kremlin came after 53 prominent Soviets appealed to him in an open letter to consider declaring a state of emergency in tense republics."Where the situation becomes especially acute, where serious threats to state security and the lives of people arise, a state of emergency or presidential rule will be necessary," Gorbachev told more than 2,000 deputies in the cavernous marble Palace of Congresses.

During the 40-minute speech, he spoke of ethnic conflicts and separatist movements in Azerbaijan, Moldavia, Georgia and the Baltic republics. He did not specify in which he thought emergency rule would be most likely.

Earlier this month, Gorbachev declared a limited form of martial law in the disputed Nagorno-Karabakh region

of Azerbaijan and in Baku, the republic's capital.

Leaders of independence movements in the Baltic republics of Estonia, Latvia and Lithuania have contended in recent weeks that the Kremlin was preparing to crack down on them.

The open letter was signed by Russian Orthodox Patriarch Alexi II, army Gen. Mikhail Moiseyev, Culture Minister Nikolai Gubenko, Deputy Defense Minister Valentin Varennikov, other lawmakers, writers and prominent Soviets. It was circulated at the Congress of People's Deputies, meeting in the Kremlin.

"We propose that urgent measures be taken against separatism, subversive anti-state activity, instigation and inter-ethnic strife using the laws and powers that have been given to you," they wrote.

It was not clear what response the letter would draw from other members of the quasi-democratic congress.