President Carter brushed aside the objections of three weavering NATO members yesterday, asserting that he expected "an alliance consensus" on deployment of new U.S. medium-range nuclear missiles in Western Europe. o

After Carter's meeting with the prime ministers of Norway and the Netherlands, White House press secretary Jody Powell said the administration expected approval of the nuclear modernization program at the NATO meeting Dec. 12 in Brussels.

Norway's Prime Minister Odvar Nordli said he came away satisfied with the president's "deep commitment" to enter into "real" negotiations with the Soviet Union on limiting nuclear weapons in Europe early next year. He indicated that Norway would vote for the modernization program next week.

Dutch Prime Minister Andreas van Agt, whose coalition government may collapse on the issue, left the final Dutch stand uncertain. Van Agt is under pressure to oppose the program and the Dutch parliament, in a non-binding vote, Thursday night rejected deployment of new U.S. nuclear weapons in Europe.

Danish Foreign Minister Kjeld Olesen again restated his government's proposal for a six-month delay on the NATO decision in his meeting with Secretary of State Cyrus Vance and national security adviser Zbigniew Brzezinski. But Danish sources said Denmark is likely to support the program next week.

Yesterday's sudden flurry of summit discussions apparently was in response to a revival of antinuclear sentiments in the three NATO countries. rU.S. officials said however, that a "very strong consensus" for deployment of 572 Pershing II and groundlaunched cruise missiles virtually assured the plan's adoption at Brussels.

U.S. officials in the meetings yesterday stressed the importance of a unanimous decision at Brussels in response to what they called an "accelerated" Soviet program of deploymet of medium-range SS20 missiles aimed at Western Europe. They expressed the hope that the Dutch would find a way to associate themselves with the program.

But, a senior official said, the basic document on nuclear modernization received ministerial approval last week and most governments will support it at Brussels irrespective of the Dutch decision. "We're determined to pursue it one way or another," he added.

The program of deployment will be accompanied by a proposal to the Soviet Union to enter into negotiations that would enable the United States to deploy a smaller number of missiles than the planned 572. These talks would be conducted in the context of the third phase of Soviet-American arms limitation talks.

Powell said that the NATO decision was mandatory because there were new indications that the Soviets were accelerating their SS20 deployment program. This has "created a gap and that gap must be closed," he said.

An administration official said later that three new SS20 sited have been discovered in the past two weeks. He said intelligence estimates now put at 700 the number of warheads these missiles could deliver from sites that are either operational or under construction.

Two-thirds of these missiles are capable of striking targets in Western Europe while the remainder are directed against targets in China, he said.

The introduction of the 1,000-mile-range Pershing and the 1,500-mile-range cruise missile would mean that for the first time since 1960s the United States would have European-based nuclear weapons capable of striking targets n the Soviet Union.

The production and maintenance of these weapons would cost the United States an estimated $2.5 billion over the next decade. The NATO allies would for infrastructure costs.

Yesterday's meetings were held against a backdrop of intense Soviet diplomatic pressure on Western Europe to reject or delay the plan. But the Soviets indicated in a recent Warsaw Pact communique that they were prepared to enter into negotiations on limiting numbers of medium-range missiles in Europe after the Brussels meeting.

The uncertain future of SALT II, whose Senate ratification has been put off until next year, dims prospects for any such immediate talks.