Secretary of State Alexander M. Haig Jr. said today the United States and its European allies must establish "a long-term framework" for dealing with the Polish crisis that will put pressure on the Soviet Union without splitting the Atlantic Alliance.

Haig, talking with reporters aboard his plane en route here, outlined the United States' goals for a special meeting Monday of foreign ministers of the 15-nation North Atlantic Treaty Organization.

He seemed confident that NATO would go along with the U.S. call for a strong statement blaming the Soviet Union for Poland's month-old martial law. But he was much more cautious about predicting whether the declaration would serve as a springboard for concerted Western sanctions against the Soviets.

"We will, for our side, feel the meeting is a success if we can achieve a common, overall approach for the long haul," he said. "It will be a success if we can establish a basis for action if the situation is not remedied in the near future and if we can instill some sensitivity to vulnerability toward phony moderation and steps which appear to be moderation."

Haig cited as examples of "phony moderation" such recent moves by Polish military authorities as "setting up model detention centers for international inspection while people languish in the real detention centers" and lifting censorship on the Western press "while privately making clear that the guy who writes tough articles will be out on his ear."

A U.S. concern has been that the West Europeans, because of trade considerations and a desire to preserve detente, would remain reluctant to back up strong rhetoric and might cite an alleged moderating trend in Poland as a reason to delay NATO action.

U.S. officials have said agreement on sanctions against the Soviet and Polish governments is unlikely from the meeting here. But the U.S. strategy is to get a tough declaration that could justify additional steps if the Polish situation remains unchanged.

Although Haig was vague in his references to a "strategic framework," there were hints that the meeting Monday might set up a working group of political and economic officials to study sanctions options.

Haig said, "What is clearly needed on the part of the West is adoption of a common, long-term stategic approach to the events in Poland--an approach which will provide a long-term framework which would prevent a failure in the East from becoming a Western failure."

Haig said the expected NATO declaration should include "a clear condemnation of the Polish junta," a "clear recognition that the Soviet Union is behind the events in Poland" and "an unequivocal reference to the blatant violations" of human rights in Poland.

The West's aim, he said, should be to prod the Soviet Union and Polish military authorities to take three steps called for by the NATO partners either individually or through the 10-nation European Community.

They are the release of those persons imprisoned since the military crackdown began Dec. 13, the end of oppression by the military and talks among the Polish government, the independent Solidarity trade union movement and the Roman Catholic Church on resuming the internal reform process that led to the crackdown.

While there is agreement throughout the NATO alliance on these aims, the question of how to achieve them has caused vexing strains between Washington and such key allies as West Germany, which has a large financial stake in trade with the Communist Bloc and feels strategically exposed to Soviet pressures.

These strains were evident when West German Chancellor Helmut Schmidt visited Washington last week. Although Schmidt made the concession of joining President Reagan in asserting Soviet responsibility for the Polish situation, he left unanswered the question of how far Bonn would support a U.S. sanctions campaign.

Haig avoided commenting directly on the problems with West Germany and whether a failure to win Bonn's approval for sanctions would mean similar problems with the other allies.

He said only: "We will continue to press, on the U.S. side, for action, although always recognizing that differences between member governments require pragmatism in determining their respective approaches."

Despite Haig's reticence on specifics, he is understood to have told Schmidt bluntly in private last week that the United States expected West Germany to meet its obligations as a member of NATO and not to act as though it has full freedom to float back and forth between the Eastern and Western blocs.