Toyota's president acknowledged the company's rapid global growth was partly behind various problems that have plagued the Japanese automaker in recent years.

Toyota Motor Corp. President Katsuaki Watanabe said Thursday the carmaker has improved quality control and is sticking to its sales targets, including those in North America, despite worries about a credit crunch and a slowdown in the auto market.

Speaking at the Japan National Press Club, Watanabe noted the reasons behind recent defects were varied, spanning development, design, production, suppliers and maintenance.