Like all its rivals, Nissan is now struggling in the US
Nissan has reported a 41% fall in half-year profits after it was hit by the high value of the yen and the "severe decline" in the US car market.
Japan's third-largest carmaker made a net profit of 126bn yen ($1.3bn; £803m) between April and September, down from 212bn yen a year earlier.
Despite seeing overall sales rise 4.7%, Nissan said those in the US fell 3.4%.
Its results came as fellow Japanese car firm Suzuki said it expects profits to fall 25% in the year to 30 March.
Blaming weaker sales in India and Europe, Suzuki said its annual net profits would probably fall to 60bn yen from its previous estimate of 80bn yen.
Looking ahead, Nissan warned that its profits for the financial year to the end of March may fall by more than two thirds.
Suzuki specialises in small-sized cars
It expects a net annual profit of 160bn yen, down from 484bn yen a year earlier, and well short of its previous 340bn yen forecast.
"The global financial and economic crisis has had a profound effect on every area of our industry, with the grip on credit and declining consumer confidence being the most damaging factors," said Nissan chief executive Carlos Ghosn.
He added that the firm was now taking "all necessary and responsible measures to protect the company and preserve our ability to rebound when conditions improve".
At the start of this week, Nissan said it would halt production of two models at its Sunderland plant in the North-East of England due to falling demand caused by the economic downturn.
It said no jobs were affected.