Toyota President Akio Toyoda has said California's new zero-emission requirements that seek to end sales of new gasoline-only vehicles by 2035 will be "difficult" to meet.

"Realistically speaking, it seems rather difficult to really achieve them," Toyoda said Thursday through a translator during a roundtable interview with reporters.

Toyoda, who has led the company since 2009, defended Toyota's strategy and electric vehicle development plans, which have been criticized by some environmental groups and investors who want the company to move faster to adopt battery electric vehicles (BEVs).