MOSCOW — Pavel Grachev, a former Russian defense minister who led troops into Chechnya in the 1990s, died on Sunday. He was 64.

Mr. Grachev, who served under the late Boris Yeltsin from 1992 until 1996, died in a Moscow hospital after being admitted on Sept. 12 in serious condition. No cause of death was immediately given.

He is perhaps best remembered for promising in 1994 to crush Chechen separatist rebels ‘‘in a couple of hours with a single regiment of paratroopers.’’

The war stretched on for more than two years, with thousands of soldiers and tens of thousands of civilians killed, and ended with the Kremlin forced to sign a peace treaty.

Accusations of corruption connected with the withdrawal of Soviet troops from Eastern Europe, although never proven in court, earned Mr. Grachev the nickname Pasha Mercedes.

He had first proved his loyalty to Yeltsin in August 1991 by switching sides during the hard-line Communist coup attempt that hastened the fall of the Soviet Union and brought Yeltsin to power. Mr. Grachev also supported Yeltsin in his confrontation with Parliament in 1993, which led to the shelling of the Parliament building.

After his reelection in the summer of 1996, Yeltsin fired his disgraced defense minister.

Mr. Grachev was a commanding officer of elite paratroopers from 1981 until 1988 during the Soviet occupation of Afghanistan.