WASHINGTON, Aug. 30 (AP) —Ambassador Agha Hilaly of Pakistan said today he could not understand the demand in the United States for an end to all American military and economic aid to his country.

The ambassador told news men such demands, particularly those made by Senator Edward M. Kennedy, were puzzling be cause there had been no substantial United States military aid to Pakistan since 1965.

He also said that elimination of economic aid to Pakistan would serve no purpose. “Cutting this off won't cure the problems in my country,” he declared.

The ambassador called a news conference to answer statements made by Senator Kennedy last week In which the Massachusetts Democrat renewed demands that the Nixon Administration end all aid to the Pakistani Government.

Mr. Hilaly said the only military assistance provided to his Government by the Nixon Administration consisted of a relatively small amount of spare parts for equipment that was given before 1965.