The two automakers had said production would be halted at least until the middle of this week, but now don't see a resumption in making vehicles before the start of next week.
Nissan Motor Co., Japan's second-largest carmaker, plans to resume production of vehicles at five Japanese plants on Thursday for as long as its supplies last.
Toyota is making components for overseas plants and replacement parts in Japan, but it hasn't produced vehicles domestically since March 14 after a massive earthquake and tsunami struck the northeastern region of Japan's Honshu island.
"A decision on when vehicle production will resume in Japan has yet to be made," Toyota said in a statement Tuesday.
Each day its Japanese assembly plants are idled represents a loss of 15,000 vehicles , according to a report from Deutsche Bank.
The impact on its U.S. plants remains limited. "All 13 North American vehicle and engine plants are running normally, although overtime has been curtailed to conserve parts that come from suppliers in Japan," Toyota said. Dealer inventories, it added, remain "generally good."
Honda previously announced a suspension in domestic auto-making until at least Wednesday but now doesn't expect to resume production before next Monday.
"Concerning operations from March 28 on, Honda will make decisions based on the status of the recovery of Japanese society as a whole as well as the supply of parts," Honda said in a statement. Detroit News