Sergio Marchionne told La Stampa newspaper that Fiat also remained committed to Italy but needed to work with the government and unions on structural problems.
Now we have to concentrate on Opel. They are our perfect partner, said Marchionne, who has emerged as a possible suitor for the German unit of General Motors Corp (GM) .
Fiat sealed an industry-changing deal with Chrysler , the smallest of Detroit's Big Three automakers, on Thursday. Fiat will take an initial 20 percent stake in Chrysler, which filed for Chapter 11 bankruptcy protection.
The objective is to strengthen Fiat and give Chrysler a chance to clean itself up, he said.
Even with the Chrysler deal, I have never given up for a second my commitment to the Italian system, said Marchionne, who has spoken of the need for consolidation in the car industry.
Together with the unions and the government we must be able to face up to the structural problems responsibly, remaining faithful to the commitments to workers, he said.
But we cannot ignore falling demand. The example that comes from (U.S. President Barack) Obama is that we have to maintain and reinforce the country's industry, but recognize the reality of things.
Any changes for Fiat's Italian business would take into account European and domestic norms, he said: I haven't turned into Marchionne the American.
Marchionne coughed throughout the interview and admitted to being tired after months of talks leading up to the Chrysler deal, adding: We worked day and night, I spat blood .
I've got to say that the situation of the market helped us a lot. The American crisis made it a possibility and opened up favorable conditions for us, he said.
So this is a perfect marriage, with a series of pieces and coincidences fitting together perfectly.
Italian Prime Minister Silvio Berlusconi, speaking in Naples, said on Friday Fiat's deal with Chrysler was absolutely positive and would help drive the country out of the economic crisis.
(Reporting by Ian Simpson; editing by Simon Jessop)