After meetings with U.S. officials, Peruvian Foreign Minister Jose de la Puente said Thursday night that the United States shows signs of having adopted a more "mature" and "professional" attitude toward its Latin American neigbors.

De la Puente's visits with Secretary of State Cyrus R. Vance, Vice President Walter F. Mondale and the Senate Foreign Relations Committee came after he received a spur-of-the-moment letter of invitation from Vance. The letter asked him to stop in Washington on his way home from an official visit to Spain.

In recent years, Latin American governments have characterized U.S. policy toward them as one of neglect. De la Puente implied, in a press conference at the Peruvian embassy, that Vance's relatively informal invitation to stop by and talk was a big step toward bettering hemipheric relations.

"It is indispensible to maintain a dialogue," de la Puente said. "Perhaps in the past, a lack of communications has given a deformed image of what our good relations should be."

According to a State Department official, the talks included a discussion of arms limitations in Latin America. The United States is "concerned," the official said, about Peru's recent purchase of 36 Sukhoi strike aircraft from the Soviet Union.

De la Puente said he assured Vance that Peru decided to buy from the Soviets only because they offered better credit terms, and that the purchase was to replace 'obsolete' equipment, not for any specific offensive purpose.