Argentina accused the United States today of interfering in its domestic affairs by reducing military aid to show U.S. unhappiness over violations of human rights here.

A Foreign Ministry statement said the reduction from $36 million to $15 million in the military aid request sent to Congress by the Carter administration showed "interference in the internal affairs of our country and a lack of knowledge about the Argentine situation."

The statement added that "no state, regardless of its ideology or power, can take upon itself the role of an international court of justice and interfere in the internal affairs of other countries."

Such action, the statement said, is "a deplorable abnormality in the conduct of international relations."

The aid cut was front-page news Friday in papers here, but there was no official reaction until today. There has been speculation, repeated today in the daily newspaper Clarin, that the military may decide to reject all U.S. military assistance.

A "qualified navy spokesman" quoted yesterday in Clarin, said the move was "another example of certain chronic weaknesses in the United States whcih we have had to get used to."

James Neilson, a columnist in the English-language Buenos Aires Herald, wrote that the $15 million remaining in aid is "a pretty insulting amount," adding that there was no reason to accept it.

"The moral vigilantes of the Carter administration, led by the President himself, are firing at everything that moves," he added.