The revoluntionary government of Nicaragua warned today that if it does not receive financial assistance from Western countries to buy arms, it will seek military aid "from the socialist bloc or elsewhere."

Among Western Hemisphere countries, only Cuba now receives outright military assistance for the Soviet Union and its allies, although Peru has made cash purchases of military equipment.

At a news conference, Sandinista guerrilla leader Eden Pastora, known as Commander Zero, said he and other Nicaraguan officials who met yesterday with Secretary of State Cyrus Vance told him Nicaragua seeks arms credits because "we have no money.... Somoza stole it all."

State Department spokesman Tom Reston, traveling with Vance, would not respond to the Nicaraguan challenge.

The Americans and Nicaraguans are here to attend the inauguration of President Jaime Roldos.

In the past, the United States has said it would not rule out military assistance to the junta that overthrew former president Anastasio Somoza, a longtime U.S. ally. But it has made clear that it first expects evidence of Nicaraguan adherence to human rights policies acceptabel to the Carter administration.

Pastora said that although Nicaragua has enough weapons to arm all the people, the new government wants to replace them because they are raeli Galil submachine guns and U.S. M16s used by Somoza's hated National Guard.

Also at the news conference were Violeta Chamorro, a member of the five-member junta that governs Nicaragua, and Foreigh Minister Miguel d'Escoto.

Pastora also responded angrily to a request by Nicaragua's bishops that the junta grant amnesty to the former National Guard soldiers they are hodling.

"How can we let out those who are murderers?" he asked. "If you had seen the unscrupulous people who - without batting an eye - led us to common graves with 50 bodies and said they had killed them...before they died they mutiliated them - cut off their genitals, their arms or legs and bled them to death.

"Don't come to us and ask amnesty for those criminals."

He said there are between 3,000 and 4,000 "war criminals" in jails in Nicaragua. "We have no political prisoners," he added. "There are plenty of Somoza supporters walking around free."

Referring to the "war criminals," he said, "They will be investigated one by one and will be tried by civil courts."

The issue of political prisoners is important to the United States, which has criticized rightist Latin American governments for violation of human rights.

Reston said the United States "will be following very closely" Nicaragua's adherence to pledges it made to the Organization of American States before taking power guaranteeing the rights of Somoza's supporters.

The Nicaraguans have expressed irritation at any suggestion that the United States put political conditions on aid.

But the one thing everyone here agrees on is the urgent necessity for money to reconstruct Nicaragua.

Even former Portuguese prime minister Mario Soares, who visited Nicaragua as the head of a committee of the Socialist International, said, "It is essential, urgent for the future of Latin America democracy," that Nicaragua receive substantial aid. Soares was also here for Roldos' inauguration.

"The new government [of Nicaragual] is not communist," he said, "but it could become communist."

"You cannot imagine the destruction there," he added. "Somoza was a criminal. He burned money, he stole all their foreign reserves. He destroyed hospitals and factories.

Reston said Vance and the leaders of the Andean Pact, a five-nation South American economic grouping, had agreed to cooperate on providing reconstruction aid to Nicaragua.

"We are in favor of trying to assist the government of Nicaragua to rebuild its war-shattered economy to provide humanitarian assistance. Many people are homeless and without food," he said.

Junta member Chamorro said reconstruction will cost "billions of dollars," all of the cities were damaged. She said the country was left with only $3 million in capital.

During his visit here Vance has taken the opportunity to meet individually with the presidents and foreign ministers of eight Latin American countries, including the most important democracies. He is trying to form a coalition of democratic nations to deal with such hemispheric issues as a policy toward the new Nicaraguan government.

Vance had breakfast this morning with Venezuelan President Luis Herrera Campins, whose country backed the Sandinista rebels.

The secretary of state then met with officials of the Andean Pact. The group was involved in the negotiations that led to the ouster of Somoza and the installation of the new Nicaraguan government.

With the election of Roldos in Ecuador and the political compromise that brought President Walter Guevara Arze to power in Bolivia this week, all but one of the Andean Pact nations now has a democratic government.

Peru's military government has promised to hold elections next year, and the two other members, Colombia and Venezuela, have had democratic governments for many years.

In recent months the United States has turned increasingly to the Andean Pact in conducting its policy.

President Carter's human rights policy has alienated the military governments of South and Central America.

Vance had been scheduled to meet during his stay here with the foreign ministers of El Salvador and Guatemala, whose right-wing military governments fell threatened by the leftist victory in Nicaragua. Vance missed both meetings because of delays in his schedule and the snarled traffic in the winding streets of Quito during the inauguration festivities. One U.S. diplomat spent much of last night searching through a huge reception in the National Palace for Salvadoran Foreign Minister Jose Antonio Rodiguez.

Reston, the State Department spokesman, said that Vance "deeply regrets" missing the meetings with the Central Americans and "will continue to solicit" their views "through regular diplomatic channels."

There was no indication that Vance had deliberately avoided seeing the two, despite the current arm's length U.S. relationship with their countries. CAPTION: Picture, CYRUS VANCE...met with Latin leaders