For the first time since martial law was imposed in Poland in December 1981, a high-level U.S. emissary visited Warsaw last week and met with Polish leader Gen. Wojciech Jaruzelski and other senior Polish officials.

U.S. and Polish officials were cautious in their comments on the visit by retired deputy secretary of state Walter J. Stoessel Jr., both sides characterizing it as unofficial.

But Stoessel, who was U.S. ambassador to Poland in 1968-72, said yesterday that his visit had been cleared in advance with the State Department. Its significance to the Poles was evident in the nearly three hours he spent with Jaruzelski.

While neither side would say so on the record, one Polish official said the initiative for Stoessel's visit had come from the United States.

U.S.-Polish relations have been largely frozen since early 1984, when President Reagan eased some of the economic sanctions that he had imposed after Jaruzelski's suppression of the independent Solidarity union movement. Warsaw has pressed for a resumption of most-favored-nation treatment for its exports, for new U.S. credits and for political talks, while Washington has urged liberalization within Poland, including the release of approximately 200 political prisoners.

All of these subjects were raised during Stoessel's three days of talks in Warsaw, which included meetings with the head of the Polish Roman Catholic Church, Cardinal Jozef Glemp, and with members of the domestic opposition. From Warsaw, Stoessel flew to Rome for a meeting with Polish-born Pope John Paul II, who follows developments in his homeland closely and has been discussing the terms for his third visit home as pope, possibly next year.

Stoessel, who returned to Washington last Saturday, has reported to officials at the State Department on his talks, but State Department spokesman Charles Redman declined to characterize them yesterday.

At the Polish Embassy here, which has been without an ambassador since Romuald Spasowski defected after Jaruzelski's crackdown on Solidarity, charge d'affaires Zdzislaw Ludwiczak called Stoessel's trip "an important visit." He added, "I hope this is the beginning of opening a political dialogue," as Poland proposed in December 1984.

That was also the month that the Reagan administration announced it was withdrawing its objections to Polish membership in the International Monetary Fund. The IMF board has yet to act on Poland's application, which is expected to be approved this spring.

Ludwiczak said IMF membership would be "very important," both because it would improve Poland's position with foreign creditors to whom it owes $29 billion and because of its "clear-cut connection" to the economic reforms that Jaruzelski's government has sought.

In many nations with foreign debt problems, new IMF credits have been conditioned on the imposition of domestic austerity programs. Poland, like many socialist command economies, heavily subsidizes many consumer products, and past efforts to raise prices of bread and other staples have led to violent political protests.

While IMF membership is no longer an issue between Warsaw and Washington, other economic questions remain on the table. U.S. officials are following talks between Poland and the private Rockefeller Foundation over a proposed church-administered fund to aid Polish private farmers. There also have been U.S.-Polish talks over proposed uses for U.S.-held Polish currency from 1980 sales of U.S. farm products.

Diplomatic sources in Warsaw said that Stoessel brought no specific proposals from Washington on any of these issues and that Jaruzelski did most of the talking during their meeting. Stoessel agreed yesterday with that description.