WASHINGTON, Oct. 1 — Senator Barack Obama will propose on Tuesday setting a goal of eliminating all nuclear weapons in the world, saying the United States should greatly reduce its stockpiles to lower the threat of nuclear terrorism, aides say.

In a speech at DePaul University in Chicago, Mr. Obama will add his voice to a plan endorsed earlier this year by a bipartisan group of former government officials from the cold war era who say the United States must begin building a global consensus to reverse a reliance on nuclear weapons that have become “increasingly hazardous and decreasingly effective.”

Mr. Obama, according to details provided by his campaign Monday, also will call for pursuing vigorous diplomatic efforts aimed at a global ban on the development, production and deployment of intermediate-range missiles.

“In 2009, we will have a window of opportunity to renew our global leadership and bring our nation together,” Mr. Obama is planning to say, according to an excerpt of remarks provided by his aides. “If we don’t seize that moment, we may not get another.”