DUBAI: Iran should invest in renewable energy to preserve its hydrocarbon reserves, Iranian energy minister Rostam Qasemi said on Wednesday, as tightening sanctions make it increasingly difficult for Tehran to sell oil.

With Iran's biggest buyers cutting imports of its crude and looking for other suppliers, Tehran says the time is right for the world's fifth largest oil producer and the second biggest gas holder to go green.

Iran's renewable sector is tiny, as in much of the Middle East where investments have been focused on building energy-hungry industry fueled by cheap oil and gas.

Iran's pressing need to reduce its own gas and oil use has also been the driving force for building the country's first nuclear power plant so that it can export more fuel.

"Reliance on hydrocarbon resources in the long run is neither possible nor meets national interests," oil ministry news website Shana reported Qasemi as saying in a statement.

"Gradual reduction of oil consumption on the one hand and a revolutionary and swift move toward using renewable energies on the other hand are the only appropriate mechanisms which can help the country," Shana reported him as saying in a statement delivered to the National Energy Conference in southern Iran.

China, the world's second-largest oil consumer and Iran's biggest customer, has been courting Saudi Arabia as it scours the globe for alternative oil supplies to replace a fall in its imports from Iran, while Korean and Japanese leaders have toured the Gulf looking for backup supplies.

Tension with the West rose last month when the United States and the European Union targeted Iranian oil exports in their efforts to halt what they suspect is Tehran's quest for an atomic bomb.