The United States is willing at next week's summit meeting of 16 Western leaders to consider joining in a pledge of nonaggression toward members of the Warsaw Pact alliance, President Bush said in an interview published yesterday.

The idea of a nonaggression pledge, first proposed by Soviet officials several weeks ago, is one of several initiatives that North Atlantic Treaty Organization leaders could take to ease Soviet concerns about a unified Germany's membership in NATO, officials said. The officials said that efforts to allay the Soviet concerns over German NATO membership will likely dominate the London summit next Thursday and Friday.

Another Western initiative being prepared for the summit is intended to provide for an expanded political role for the 35-nation Conference on Security and Cooperation in Europe, officials said. The Soviet Union has urged that the group, now a loose-knit organization, should become the central forum for European security discussions.

NATO leaders have rejected this idea, but officials say the alliance likely will approve a plan to give the group a permanent staff, a schedule of regular meetings, and an expanded role in promoting human rights, preventing conflicts, and monitoring elections and arms control agreements.

"I think there are ways in which it can become very clear to what's left of the Warsaw Pact and . . . a restructured NATO . . . that there won't be any threat to each other, and maybe there can be some declaration" that would fall short of a formal treaty, Bush said in an interview Wednesday with European and Japanese journalists.

While declining to give the idea a blanket endorsement, Secretary of State James A. Baker III told reporters at the White House yesterday that a declaration of "nonaggression, defensive intent, peaceful intent" from the NATO alliance to individual members of the disintegrating Warsaw Pact alliance is "the kind of thing that you'll see discussed at the NATO summit."

Several officials said Bush's statement about the idea caught the State Department by surprise. Baker said a week and a half ago, after the idea was promoted by Soviet Foreign Minister Eduard Shevardnadze, that it had positive as well as negative aspects.

West German Chancellor Helmut Kohl recently said he will urge the leaders to endorse a nonaggression declaration, and British Prime Minister Margaret Thatcher has also endorsed the idea, U.S. and diplomatic officials said. But officials in France and several other countries have expressed concern that such a statement would imply parity between NATO and the crumbling East-Bloc alliance.

Kohl has said this can be avoided if the Western declaration is made to members of the Eastern alliance, rather than to the alliance itself as suggested by some Soviet officials.

U.S. officials cautioned that the meeting probably would not fulfill a stated goal of establishing detailed plans for future East-West negotiations on short-range nuclear weapons in Europe. Baker said yesterday that it would more likely "kick off" a review of these objectives.

The officials said this decision followed a general Western consensus to avoid fractious debate over U.S. nuclear weapons deployments in Europe at a time when Kohl, who is preparing for a German election in December, is particularly vulnerable to public, anti-nuclear sentiments.

Baker said the summit would also begin a review of NATO's conventional, or nonnuclear, force deployments in light of an expected East-West arms accord later this year. But officials were uncertain yesterday whether the leaders would fulfill an earlier plan to propose future limitations on troops in a united Germany.

Bush said that he felt in these discussions a "disproportionate responsibility to convince {Soviet President Mikhail} Gorbachev" that German membership in NATO "is not threatening to the best interests of the Soviet Union." He added, however, that he expects the summit to embrace ideas that will refine NATO's current mission, rather than "radically alter" it.

Bush, who departs today for his home in Kennebunkport, Maine, will be joined on Monday by Baker, national security adviser Brent Scowcroft, Defense Secretary Richard B. Cheney, Joint Chiefs of Staff Chairman Colin L. Powell and Vice President Quayle. These officials are expected to give Bush a series of briefings before his departure for London on Wednesday.

Cheney plans to leave Monday for discussions with officials in Norway, Greece, Turkey and Portugal.