The NATO allies today urged the United States to offer new arms control initiatives, which would include positive elements from the Soviet leadership's latest proposals, to enhance prospects for a successful superpower summit and progress in Geneva negotiations on nuclear and space weapons.

Secretary of State George P. Shultz, consulting here with foreign ministers of the North Atlantic Treaty Organization before next month's meeting between President Reagan and Soviet leader Mikhail Gorbachev, also picked up strong backing for a "narrow interpretation" of the 1972 Anti-Ballistic Missile Treaty as it applies to the U.S. space defense research program known as "Star Wars."

Shultz said the allies responded with "universal happiness" when he informed them that Reagan upheld a restrictive approach to compliance with the ABM accord last week, even though some U.S. policy makers argue that a much broader range of testing and development is permissible under the treaty.

Earlier suggestions by Robert C. McFarlane, the White House national security adviser, that the administration might relax its adherence to the ABM provisions evoked widespread anxiety among the Europeans that the treaty, seen as one of the last foundations of arms control, would soon lose all meaning through cumulative Soviet and American violations.

Shultz, who flew here from San Francisco where he delivered a speech yesterday reaffirming the stricter ABM interpretation, said, "We have designed our research program to fall within the narrow definition of ABM treaty provisions and we intend to keep it that way."

Shultz said the State Department legal adviser, Abraham Sofaer, who accompanied him here, had studied the treaty carefully and found "lots of room for varying interpretations."

But any decision to develop and deploy space defense weapons in response to successful research findings, Shultz emphasized, would only follow "extensive consultations with the allies and negotiation with the Soviet Union."

Today's talks were convened at the request of Belgium and the Netherlands, which were irked at being excluded from Reagan's meeting next week in New York with the leaders of five industrialized democracies. France has declined the U.S. invitation to that meeting.

European diplomats said that while they were reassured by Shultz's comments, the shape of the administration's long-term policy remains unclear. They said the NATO meeting was useful in providing Shultz, who is perceived as more sympathetic to the allies' interests, with "ammunition" to use against Pentagon hard-liners on arms control.

Some delegates here compared the consultation with a similar meeting in Portugal last June, after which Shultz told the president that the allies unanimously supported continued adherence to the provisions of the SALT II accord. Reagan agreed to do so against the wishes of Pentagon hawks.

But the Europeans appear to feel less certain of Shultz's influence at this time, barely a month before the Geneva summit. "It's like a carousel," commented West German Foreign Minister Hans-Dietrich Genscher about the policy battles in Washington. "We never know who is on the horse."

Several European ministers stressed that the United States should assume an active posture in advance of the summit by seeking fresh ground for compromise in arms control and not permit the Soviet Union to gain the upper hand in public opinion.

Shultz said he shared the qualified optimism expressed by the allies, though he and other senior administration officials have warned about the "fine print" beneath the basic Soviet offer.