Carlos Ghosn, chairman of Nissan Motor and Mitsubishi Motors, says the government's policy to promote eco-friendly vehicles remains murky and unclear.
While the government has an ambitious plan for electric vehicle production, Mr Ghosn said yesterday at an international media roundtable in Bangkok that it has yet to show any clear signs of willingness to promote such cars in the country.
"The willingness to generate electric cars should focus on the core (mass) market, not the premium vehicle segment, because using electric cars in the core market will better respond to environmental demands," he said.
"The policymaker itself should show its willingness to promote the proliferation of electric cars in the market."
Mr Ghosn said China, for example, is now one of the largest electric car markets for Nissan, where the company has introduced low-cost electric cars on account of the strong policy and commitments from the Chinese government.
He said there has been progress on electric cars in the US, Britain, France and Japan, largely thanks to the governments' clear-cut promotional policies and measures.
But Mr Ghosn said Thailand will remain an important market for Nissan and Mitsubishi, citing the country's strategic location for producing cars both for the domestic market and export.
In Thailand, Nissan has a production capacity of 370,000 vehicles per year at its facilities in Samut Prakan, while Mitsubishi can make 510,000 vehicles annually at its plant in Chon Buri.
Mr Ghosn said his first priority for Thailand is to optimise Nissan and Mitsubishi's existing capacity, which they have invested in for decades.
The Nissan plant in Thailand runs at about 50-70% of production capacity both for domestic sales and export, while the Mitsubishi's plant focuses mainly on the export market.
For the last fiscal year ending March, Mitsubishi made 356,000 units of completely built-up vehicles, mainly for shipments to Europe, Asia, North America and Oceania.
Mr Ghosn said he wants to boost market share for Nissan and Mitsubishi in Thailand to double digits in the short term, up from 5.6% and 7.2%, respectively.
Nissan sold 42,677 units last year, down 16.6%, while Mitsubishi's sales stood at 55,409 units, down 7.4%.