Senior Contra officials said the Bush Administration plans to cut off all aid to the Nicaraguan rebels’ political leadership beginning Aug. 15, but Contra director Adolfo Calero insisted that the aid is only being reduced. In Miami, Silvio Arguello, vice president of the Contras’ political assembly, said U.S. officials told the leadership of the plan at a meeting near Washington. The cutoff would cover about $260,000 per month used to pay salaries of the six-member Contra directorate and other expenses at the rebels’ Miami office, according to a Contra official who asked not to be named. But in an interview with CBS Radio, Calero denied that the cutoff would be total. Apparently unaffected by the U.S. move is a $49.7-million package that Congress approved last April for Contra troops.