Retired Maj. Gen. Hugo Carvajal of Venezuela, a close confidant of the country's late socialist president, Hugo Ch?vez, pleaded not guilty to drug trafficking charges in a Manhattan courtroom Thursday.Carvajal, 63, is accused of having smuggled 12,300 pounds (6.15 tons) of cocaine into Mexico aboard his private jet in 2006.U.S. Attorney Damian Williams accused Carvajal