Japanese automakers including Toyota Motor Corp <7203.T> and Nissan Motor Co <7201.T> said on Tuesday it would be some time before they could return to full production after Japan's devastating March 11 earthquake and tsunami disrupted supplies to their plants.

With some 500 parts affected, a Toyota spokesman said it was impossible to say when production would resume in full. A source with knowledge of the matter told Reuters that the automaker had told its main suppliers not to expect production to restart until at least April 11 -- exactly a month from the quake.

All vehicle assembly has been halted at the 18 domestic factories that build Toyota and Lexus cars except for two plants that began producing a limited number of three hybrid models, including the Prius, on Monday.

Meanwhile, Nissan CEO Carlos Ghosn told workers at one of the company's factories in the stricken northeast he wanted to bring the site back to full production levels by early June at the latest.

Speaking at an engine factory in the city of Iwaki, about 50 km (30 miles) from the stricken Fukushima Daiichi nuclear plant, where workers are battling to control radiation leaks, Ghosn said he had no intention of closing the site, a Nissan spokesman said.

Ghosn said he wanted to have the factory ready to start production by the end of April and to resume full production in June, while keeping an eye on suppliers.

The No. 2 Japanese automaker earlier told Reuters it aimed to manufacture on a normal process basis, with deliveries to come from suppliers from mid-April, but added that deliveries of some parts may take longer to return to normal.

The earthquake off Japan's eastern coast damaged some assembly and parts factories in the northeastern region, causing an industry-wide production loss of at least 400,000 vehicles to date in Japan.

Analysts expect the effect to ripple across overseas production and non-Japanese automakers will also be hit as inventories of parts dry up in the coming months.

A spokesperson for Honda Motor Co <7267.T> said on Tuesday that car production would be suspended until the end of the week and that the company was considering when it could re-start output.

Honda said it needed to examine when suppliers will able to resume deliveries of parts and what their inventory levels are. The company has suspended exports of parts.

Toshiyuki Shiga, Nissan's chief operating officer and the chairman of the Japan Automobile Manufacturers Association, told the Wall Street Journal the auto industry should be able to get a full picture of the parts-supply network by mid-April.

(Writing by Dhara Ranasinghe, Editing by Lincoln Feast and Joseph Radford)

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