Secretary of State Cyrus Vance today continued a high-level U.S. effort to calm European worries about how their security will be affected by future U.S.-Soviet arms agreements.

Following a theme struck yesterday by Defense Secretary Harold Brown before NATO defense ministers, Vance said the United States was listening to its allies, was aware of their concerns and would work with them in developing policies for negotiating with Moscow.

Vance made his remarks behind closed doors at the opening session of a two-day, semi-annual foreign ministers' meeting of the 15 nations of the North Atlantic Alliance.

Vance, according to a U.S. official, told his fellow delegates that the framework now being developed for a proposed new SALT agreement with the Soviets was intended to insure that the mutual concerns of the United States and its allies were met.

Although no major new decisions are expected from the foreign ministers and none were made at the just-concluded defense ministers' session, these gatherings have taken on a unique and important quality for both the United States and its allies. This is because European interests are now more specifically involved in U.S.-Soviet arms discussions than in the past and also because the allies are worried that what the Carter administration is doing on SALT could help congressional critics of the administration.

Although the allies do have some concerns, they appeared to be going out of their way here to show support for the U.S. efforts, and to compliment the Americans on the degree and level of consultation.

Both British and West German officials offered strong endorsement of U.S. efforts.

British Foreign Secretary David Owen, according to British officals, went so far as to warn the ministers that it was now important not to feed the critics of the SALT process who were most concerned with some of the minutiae of the bargaining at a time when the allies should be championing the cause of arms control.

Although Vance told the gathering that there were still major unresolved issues, he said the United States would continue to resist including all so-called forward-based systems in these agreements.

This refers to such weapons as short-range missiles and jet fighter-bombers based in Western Europe or at sea and capable of striking Soviet territory. These are meant to counter Soviet forces targeted at Western Europe.

Initial SALT agreements and the new SALT II pact which may be agreed upon soon both exclude these weapons. These pacts are limited to long-range missiles and bombers.

The forward-based systems issue, however, embodies precisely the kind of thing that is now troubling the Europeans.

They feel that after a SALT II agreement, there will be nothing much left to talk about that will interest the Soviets except curbing these forward systems, which are intimately tied to European security.

Furthermore, a major new U.S.-developed weapon - the cruise missile - whose link to forthcoming SALT agreements is still undecided, also may eventually become one of the forward systems.

Thus the Europeans, while not wanting to upset U.S.-Soviet negotiations, are increasingly eager to have their voice heard.

Vance and Defense Secretary Harold Brown both assured the Europeans that they would be consulted before any permanent new SALT deal with the Soviets is sealed and that the cruise missile will not be traded away if military security requires that the West have it.

Nevertheless, as one top NATO official said, the concern here is that things supposedly temporary - such as the proposed three-year ban on deploying the cruise missile - have a way of becoming permanent.

There is also mounting pressure here - especially from West Germany and Britain - for a new allied effort to break the stalemated talks in Vienna aimed at mutual and balanced East-West troop reductions in Europe.

Vance, in discussing the Vienna talks, suggested that NATO seek a better balance in its own forces as well as trying to achieve a balance with the Soviet bloc. This was said to be a vague warning to NATO countries to do more to help take the burden off West Germany, which now provides the biggest share of European ground forces.

One top European NATO official said privately that the U.S. record of consultation by both Vance and SALT negotiator Paul Warnke has been "impeccable" in the past several months and considerably better than during previous administration.

If anything, he added, some Europeans have a problem in understanding some of the things that are said here, so that by the time they go back to their governments, the negotiations with the Soviets have already moved ahead.