The legendary investor and Berkshire Hathaway Inc. chief executive, in a CNBC interview, said he expects Europe's economy to have improved 10 years from now, but getting there would be difficult.

Buffett, who put $5 billion into Bank of America Corp. earlier this year, comes up whenever there is talk of a large European bank needing to raise capital, particularly in the current environment of writedowns on sovereign debt.

But he told CNBC that he would need to understand those banks better before investing in them, and that he has not yet seen an investment opportunity there in which he wants to take part.

In a wide-ranging interview, Buffett said he expects that Republican Mitt Romney will be his party's nominee for president in next year's U.S. election. Buffett has recently been raising funds for U.S. President Barack Obama.

He also reiterated his position that the economy will improve when the housing market turns around. That turn will come, he said, when the country starts creating more households than houses.

Berkshire has a number of housing-related businesses, including operations in carpet and brick, that he has said are doing as poorly as ever in the current environment.