LISBON, SEPT. 11 -- Portugal will call for renegotiation of a treaty that gives the United States use of a strategic mid-Atlantic air base because the government is dissatisfied with the amount of U.S. military aid the country is receiving, a government official said today.

Lisbon's tough stance aligns Portugal, one of the United States' most loyal allies in the North Atlantic Treaty Organization, with Spain and Greece in putting pressure on the Reagan administration to pay higher prices for military facilities in southern Europe.

{Spanish Defense Minister Narcis Serra said Thursday that Spain seeks to reduce the presence of U.S. soldiers "to the minimum level necessary," The Associated Press reported from Madrid, quoting the daily newspaper El Pais.}

Fernando Lima, a spokesman for Prime Minister Anibal Cavaco Silva, said Portugal will insist on renegotiating the treaty in February, the earliest date possible under the terms of an accord that gives the United States use of Lajes Air Base on the Portuguese Azores islands.

Cavaco Silva believes the United States has failed to honor an understanding contained in letters exchanged by the two governments that military aid would increase yearly, Lima said. The treaty itself commits the U.S. government only to using its "best efforts" to secure aid for Portugal.

The Reagan administration has blamed Congress for forcing it to cut military aid to Portugal by more than a third of the amount originally proposed for 1987.

U.S. military aid to Portugal decreased from $208 million in 1985 to $189 million in 1986. This year the amount will fall to $147.4 million, although the administration had proposed $224.4 million.

The Lajes air base is used for monitoring Soviet submarine movements in the North Atlantic and for refueling flights from the United States to Europe, Africa and the Middle East.

The United States has leased the base since 1951. The agreement was renewed most recently in December 1983 for a seven-year term. A clause allows either country to ask for a renegotiation after Feb. 4, 1988.

"The government is calling for a renegotiation as soon as the treaty allows," Lima said.

But he added that a recent report that Cavaco Silva was considering asking for an annulment of the accord had been exaggerated. "The prime minister is not threatening to break the agreement," he said.

In a televised news conference with European journalists yesterday, Assistant Secretary of State for European and Canadian Affairs Rozanne L. Ridgway said that severe cuts made by Congress in the security assistance program kept the administration from giving Portugal the level of military aid it considers appropriate.

"It even goes beyond Portugal," Ridgway said. "We are very concerned that the reductions in levels of security assistance will have a global impact for the United States."

Ridgway added that the position of the Portuguese prime minister was "entirely understandable."

She said, "The terms of the agreement provide for a review, and if Portugal decides that this is what it wishes to have, we will be there to participate."

Cavaco Silva's stand on the base agreement comes less than two months after his center-right Social Democrats won a landslide election victory, becoming the first party to secure an outright parliamentary majority since Portugal returned to democracy in 1974.

Since his election triumph, the 48-year-old premier has expressed determination to defend Portuguese interests in trade and other international affairs.

His stand on the Azores base indicates the United States would face extremely tough negotiations if it approached Lisbon to seek the transfer of a squadron of U.S. F16 fighter jets from Spain to a base in mainland Portugal.