NATO leaders reacted cautiously to the Polish government crackdown on the independent trade union Solidarity, as Pope John Paul II made an emotional appeal for a peaceful solution to the crisis in his homeland.

The pontiff alluded to the plea to avoid bloodshed made by the Polish leader, Gen. Wojciech Jaruzelski, as he announced a state of emergency yesterday. Echoing Jaruzelski, the pope said Polish blood "cannot be spilled because too much has already been spilled, especially during the last war." Three million Poles lost their lives in World War II.

The Western allies were expected to discuss the situation in Poland at a special meeting in Brussels Monday of NATO ambassadors and a previously scheduled meeting in London of the foreign ministers of the European Economic Community. Details on Page A12

France took the lead among NATO members in warning of possible "serious repercussions" and expressed the "very gravest concern" of the new Socialist government.

Noncommunist French labor unions mapped out strategy for a nationwide protest Monday and a vast spectrum of the country's political leadership spoke out against the suspension of civil liberties in Poland that Solidarity had been fighting to wrest from the country's Communist authorities for the past 17 months.

While the French Communist Party refused to participate in the demonstration, the Italian Communist Party, the largest in the West, voiced its alarm about the situation in Poland and said, "Every aspect of the way the Polish government has chosen to solve a political problem must be condemned."

Vatican sources said the Polish-born pope rose before dawn to follow reports from Warsaw on the imposition of martial law and the government's crackdown on the independent Solidarity labor movement.

Because of the cut in communications with Poland, he was not able to contact Catholic leaders in the country. Last night, he was briefed on the crisis by Italian Foreign Minister Emilio Colombo.

In a brief speech to 200 Polish pilgrims in a crowd of 30,000 gathered in St. Peter's Square for his regular noon blessing, the pontiff said, "Events of the last few hours require me to turn my attention once again to the cause of our homeland and to call for prayers." He said he was putting his homeland in the care of the Black Madonna of Czestochowa, patron saint of Poland.

According to legend, the Black Madonna, revered by the country's overwhelmingly Roman Catholic population, fended off a Swedish invasion centuries ago when Polish troops brandished a likeness of the madonna in battle.

The pontiff, whose triumphant visit to his homeland in June 1979 was credited with giving impetus to to the free trade union movement, had accepted an invitation from the Polish church to visit the Black Madonna's sanctuary at Jasna Gora next August for 600th anniversary celebrations. Vatican sources said yesterday it was too early to predict whether he would now make the trip.

In Western European cities including Paris, Vienna, Milan, Oslo, Brussels, Athens and Rome, thousands of Solidarity supporters staged sympathy demonstrations and labor leaders demanded the immediate release of detained officials and Solidarity supporters.

French Premier Pierre Mauroy warned of "serious repercussions" if Poland's "movement of renewal" were aborted by yesterday's crackdown. Terming the military moves "an interruption of Poland's democratic evolution," he said his government was following events with "the very gravest concern."

Mauroy's remarks, broadcast on national radio and television, followed by hours a Foreign Ministry statement saying France "deplored" yesterday's events in Poland.

Significantly, however, powerful Communist Party labor organizations refused to participate in planning with other French unions, testifying to the embarrassment of the party at the military crackdown.

The degree of embarrassment was evident in in the cautious ambiguity in a statement last night by party leader Georges Marchais calling on party members to "abstain from all initiatives that could disturb the necessary search for a peaceful resolution to the crisis."

The French Communist leader said that while his party had followed Polish efforts at "economic, social and democratic reform" with "interest and sympathy," he considered it a shame that the process had been impeded by difficulties that led to yesterday's events.

He warned that "nothing should be done that would encourage internal confrontation or external intervention" in Poland.

Austria, which recently restricted the flow of Polish refugees, dropped the curbs as Chancellor Bruno Kreisky announced, "Austria will continue to grant asylum to political refugees, no matter how many turn up on our borders."

In China, the New China News Agency reported the crisis without comment but said Chinese leaders were paying close attention to developments.

Foreign exchange markets in the Middle East, meanwhile, reflected investors' apprehensions as the dollar rose slightly with the movement of funds out of European currencies.