U.S., Russia should keep strong nuke pact: Gorbachev

CAMBRIDGE, Massachusetts (Reuters) - Former Soviet President Mikhail Gorbachev said on Tuesday a pillar of the arms control system could fall if Washington and Moscow replace the landmark START nuclear arms reduction treaty with a less formal pact.

The START treaty, signed in 1991, set ceilings on the size of the Russian and U.S. nuclear arsenals and became a symbol of the end of the Cold War. Washington has indicated it will not extend it in 2009 but wants to replace it with a pact that eliminates strict verification requirements and weapons curbs.

"I don't see a negotiating process actually happening," Gorbachev, who signed the START treaty with then-President George Bush, the father of the current U.S. president, told a Harvard University forum.

Gorbachev commented only briefly on the big majority won by President Vladimir Putin's United Russia party in Sunday's parliamentary election, saying Putin had "really rescued" the party. "Putin came to their help," he said.

Diplomatic analysts have said a U.S. position on START reflects U.S. President George W. Bush's practice of repudiating arms control as a means of curbing nuclear weapons while relying more on measures like export controls, interdiction and sanctions.

Russia has said the treaty should be replaced with a formal, binding pact, and not an informal arrangement.

Gorbachev said verifying and inspecting each country's nuclear arsenals was crucial. "It is totally wrong to declare that this system is obsolete and unnecessary after the end of the Cold War," he said. "It is totally wrong."

Gorbachev also said another milestone arms control pact, the Intermediate-Range Nuclear Forces Treaty which he signed with Ronald Reagan in 1987, must be preserved.

(Editing by Patricia Zengerle)