MOSCOW - When President Ronald Reagan proclaimed the Soviet Union an "evil empire," some saw it as political theater, a Cold Warrior's script. Yet former Soviet leader Mikhail S. Gorbachev said yesterday that the American president was sincere - an honest rival and a friend.

By the end of the superpower rivalry, the leaders had formed a partnership that steered their superpower nations away from nuclear brinkmanship.

Both men feared that their countries were heading for a nuclear conflict, and their complicated negotiations helped shift course away from potential catastrophe, said Gorbachev, who won the Nobel Peace Prize for his work in reforming the Soviet Union and easing world tension.

"I take the death of Ronald Reagan very hard," Gorbachev said. "He was a man whom fate set by me in perhaps the most difficult years at the end of the 20th century."

Those were years, Gorbachev said, "when everyone felt that we lived under the threat of nuclear conflict, and it felt as if the arms race was spiraling out of control, that we couldn't control the military machine properly."

"He has already entered history as a man who was instrumental in bringing about the end of the Cold War," Gorbachev added.

Despite Reagan's often-forceful statements against the Soviet Union, Gorbachev said he also had a personal warmth that bolstered their relations.

"In terms of human qualities, he and I had, you would say, communicativeness, and this helped us carry on normally," Gorbachev said. "But when you talk about friendly relations in politics, it's not the friendship of schoolmates."

The friendship developed out of decades of enmity, and in early days Reagan aimed some of his strongest comments at the Kremlin.

The American president issued his historic "evil empire" remark in 1983, before Gorbachev took power from the obscurity of the back benches of the ruling Soviet Politburo.

"He was sincere," Gorbachev said of Reagan's rhetoric.

Gorbachev did not escape the verbal stings. Standing by the Brandenburg Gate on the West Berlin side of the wall that divided the city, Reagan challenged the Soviet leader with the famous declaration: "Mr. Gorbachev, tear down this wall!"

Reagan began the "star wars" missile-shield initiative, rejecting the long-standing nuclear doctrine of "mutually assured destruction," which was built on the concept that neither superpower would start a nuclear war because of the certainty of deadly retaliation.

Gorbachev, meanwhile, was struggling to halt the Soviet Union's slow but relentless economic deterioration. Trying to initiate a Soviet response to the U.S. missile-shield program was a heavy burden on a Kremlin treasury strained by the inefficient Soviet command economy.

"To use the terminology of those years, he was a hawk. Nevertheless, that hawk loved life, he was man who respected traditions, and I think he was concerned about how he would be remembered in history," Gorbachev said. "It was his goal and his dream to end his term and enter history as a peacemaker."