LIMA, June 1 (Xinhua) -- Bolivian President Evo Morales said on Thursday that he had asked the United States to renew its tariff preferences for Bolivian goods before his country could reach a trade agreement with Washington in the medium term, according to reports reaching here.

    During a meeting with business leaders, Morales said he had made the request in a letter to the U.S. government.

    The 1991 Andean Trade Promotion and Drug Eradication Act (ATPDEA), which allows Andean countries to sell their products to the United States with a zero tariff in exchange for their cooperation in fighting drug trafficking, expires at the end of this year.

    Peru and Colombia hurried to sign free trade agreements with Washington before the ATPDEA ran out, but similar talks between Ecuador and the United States have stalled and those with Bolivia never began.

    Morales said that in his letter to Washington he had explained his Cocaine Zero program, which bans using coca leaves for drug production and trafficking.

    The letter said that Morales had arranged with peasants to "rationalize" coca plantations so that coca leaves would only be used as food and traditional purposes.

    Morales is considered to be on Washington's black list because of his close relations with Hugo Chavez, the left-wing president of Venezuela, and Cuban leader Fidel Castro.

    Morales said his US counterpart George W. Bush had rejected his invitation to take part in the inauguration of the Bolivian constitutional assembly.

    In another development, Morales' spokesman said that the government was investigating reports that the United States had attempted to kill him. Enditem