Bolivian officials at a conference on illegal drugs in Vienna are planning to ask the UN to remove the coca plant from its list of dangerous drugs.
Bolivians say coca leaf use is a long tradition in their country
The UN's International Narcotics Control Board has called on Bolivia to ban coca chewing, and the use of the plant in products such as tea.
Bolivia says such a ban would be an attack on its culture.
Analysts say much of Bolivia's coca harvest goes into cocaine, making it the world's third-largest producer.
Bolivians call coca "the sacred leaf".
They say it has been used by indigenous peoples for centuries to alleviate hunger and tiredness, for medicinal purposes and in religious rituals.
UN conventions list coca as a dangerous substance, along with cocaine and opium.
Last week, an annual report by the International Narcotics Control Board reminded Bolivia that coca leaves could legally be used for medical and scientific purposes only.
Bolivia, and neighbouring Peru, should "abolish or prohibit activities... such as coca leaf chewing and the manufacture of coca tea", the report said.
The report has sparked outrage in Bolivia.
"We won't accept it because coca is our culture, our tradition. We will defend it because coca for us is also food," said Geronimo Meneces, Bolivia's Vice-Minister of Coca and Integral Development.
Bolivian President Evo Morales has agreed to reduce the number of coca plantations, limiting production for "traditional" uses such as leaf chewing and tea.