In an angry speech today on the steps of the Army's massive headquarters here, President Leopoldo Galtieri stressed Argentina's "unequal battle against the extracontinental aggressor" and said his country would obtain military aid "from other parts of the world" if necessary.

"The armed forces of our brother nations of America have fought at our side, and at the right time could fight again--and, if necessary, those from other parts of the world could do so ", he said.

The strong hint that Buenos Aires could seek Soviet aid is the latest effort by the Argentines to pressure the United States into backing off from its support of Britain in the Falklands conflict. Diplomats here, however, doubt that the fiercely anticommunist junta would forge an alliance with the Soviet Bloc.

Galtieri emphasized what he called the "disproportionate" and "unequal" nature of the battle between Britain and Argentina, as both official and unofficial accounts of the fighting seemed to be preparing the Argentine public for a major defeat.

The joint chiefs of staff, in a communique, acknowledged fo the first time that the British troops on East Falkland number between 4,000 and 4,500 and that the British had "consolidated" the beachhead at San Carlos on the island.

"The British have continued to disembark material and personnel as fast as they are able in the area,"the communique said.

The high command also reported continued fighting today and said that Argentine planes, in support of ground forces, were bombing British positions at Goose Green, three miles south of Darwin.

The official news agency Telam, citing military sources, said Argentine troops at Goose Green were outnumbered 3 to 1 after British helicopters took advantage of low cloud cover to fly in troops and provisions from San Carlos.

A high-ranking military source was quoted in Noticias Argentinas, an independent news service, as saying that the British were trying "with desparation" to achieve a military success because of serious losses to their Navy. Argentine officials contend that Britain has lost half of its naval force.

Military sources attributed yesterday's British advance on Goose Green to bad weather that prevented Argentine planes from attacking during the afternoon.

Galtieri's speech to hundreds of soldiers and officers assembled this morning to celebrate "Army Day" pointedly criticized the United States without naming it directly.

Departing from his prepared text, Galtieri shouted hoarsely into the microphone, denouncing "the open or whispered arrogance of those who exercise political, military, economic or financial pressures and who have lied and belied principles that they have never upheld."

Argentina has accused the United States of betraying the principle of diplomatic solidarity and mutual defense in the Western Hemisphere, embodied in the so-called Rio Treaty. Beyond that, the Argentines believe the United States is betraying its own anticolonial past.

"It is indispensable to note," Galtieri said, "in order to characterize this paradoxical crisis of values, the incomprehensible attitude of certain governments, which, subordinating their proclaimed principles to dark interests and dubious compromises, rationalizes or assists the aggressor in a decision that is practically unprecedented since the end of the Second World War."

In an apparent reference to U.S. involvement in Vietnam as well as to Britain's colonial past, Galtieri praised the Argentine Army, "which has never had mean intentions or spurious ambitions . . . never crossed seas, nor penetrated faraway jungles nor deserts, nor pursued obscure and incomprehensible interests."

Britain's Gurkha troops, a traditional British fighting force recruited from Nepal, have roused a kind of horrified curiosity among the Argentine public and media. Galtieri pointedly noted that the Argentine Army "does not have mercenaries among its ranks, nor does it count on surreptitious nor compulsive assistance, because it only consists of Argentine men, willing to fulfill their oath to uphold stoutly the nation's flag, even unto death."

As Galtieri spoke to the assembled troops from a red-carpeted landing framed by huge white columns, a frigid wind whipped 20 flags on the balcony above him. The honor guard of the different services, dressed in a dazzling array of gold-braided brass buttons and red-sashed uniforms, stood at attention.

It was a media event that would have made an American politician envious. For the first time in weeks, the military provided special platforms for television cameras to record the scene. Like the Navy, Air Force and Independence Day celebrations of the past three weeks--the only times that the junta has appeared publicly--the day was a curious mix of militaristic patriotism and Roman Catholic ritual.

Before Galtieri's speech, a brass band played the national anthem, and the young soldiers sang lustily, "Oh, we vow to die with glory." A white-robed priest, the Army chaplain, prayed that "our soldiers not vacillate in combat" and that the soldiers "will die with smiles on their lips as did the martyrs and saints."

In his speech, Galtieri called Argentina a "peace-loving country," and said, "Nobody, and even less so the enemy, can doubt the outstanding efforts made by our country to prevent this war . . . during 149 years [of British rule of the islands] and after that historically inexorable April 2," the day Argentina invaded the Falklands.

While declaring that Argentina will continue its effort to be flexible in the negotiations, Galtieri said, "Meanwhile, the country's arms will continue fighting against the enemy for every Argentine portion of land, sea and sky, with growing courage and efficiency, because the soldiers' bravery is nourished by the blood of his fallen brothers and by the conscious patriotic fervor of a nation united as never before in its history, determinedly leading him to fight."

Galtieri seemed far from acknowledging defeat. He thanked his troops, praising their "courage, which has surprised the whole world and which has deeply upset the intentions and arrogance of the invader."

The Argentine cause has become the cause of the Americas, according to Galtieri. "I should repeat, Argentina does not need mercenaries because the world's weaponry would not be sufficient for all volunteers, both men and women, who are requesting to take part in this fight," the Argentine leader said.

"I have no more weapons, nor cannons, nor tanks for them. We have no more ships nor planes to be manned. If we had them, we would be and armed force made up of millions, ready to fight for this legitimate right to defend what is ours."

After the speech, Galtieri, brass-tipped walking stick in hand, reviewed the troops, including a squadron of women soldiers with black berets and combat fatigues. Together with the two other junta members, Navy commander Jorge Anaya and Air Force commander Basilio Lami Dozo, he attended mass at the military chapel afterward.

The high-ceilinged chapel was filled with uniformed generals and admirals as the junta sat in thronelike chairs directly in front of the altar. Television cameras were allowed in the church to film the kneeling at prayer. As before, no one except the officiating priest took communion.

The celebrant, Bishop Jose Medina, pleaded for "respect to human beings whether they are on our side or on the other side."