A decision on when vehicle production will resume in Japan has yet to be made, Toyota said in a written statement. The disaster damaged nuclear power plants north of Tokyo and is believed to have killed at least 10,000 people.
Earlier in the week, Toyota said it would halt Japanese production through March 16. But the severity of the destruction caused by the quake and tsunami has strained relief efforts in the northeast region of the country, where the damage is most severe.
The halt in production comes at a difficult time for Toyota, which has seen its sales fall in the U.S., following massive recalls of its vehicles that began in late 2009 and have continued into this year.
Toyota stands to lose $73 million a day as long as its Japanese plants remain idle. Further, a rise in the value of the yen has made it more expensive for Japanese manufacturers to sell their goods overseas, putting a pinch on profits, including those at Toyota.
"The direction of the Japanese yen over the next three to six months as a result of this catastrophe will also affect the profitability of Japanese automakers," according to a report by Fitch Ratings, cited by the Reuters news agency.
Toyota's largest domestic rival, Nissan Motor (NSANY), said it would restart two plants on Thursday and Friday, but production beyond that remained uncertain, Reuters said. Other plants would take longer to get back on line.
Japan's third largest automaker, Honda Motor (HMC), has also idled plants, according to Reuters. On Wednesday the company reiterated its plans to suspend all production in Japan until at least Sunday.