WASHINGTON — Representative Charles B. Rangel said on Wednesday that “cultural and language barriers” had hindered him from understanding the finances of his Dominican Republic beach house, and vowed to repay several thousand dollars in federal taxes he owes after failing to report $75,000 in rental income from the villa.

At a Capitol Hill news conference, during which he was by turns remorseful and combative, the congressman said that he had not been aware of the income and unpaid taxes in part because he had trouble getting detailed financial statements from the resort’s managers in the Dominican Republic.

“Every time I thought I was getting somewhere, they’d start speaking Spanish,” Mr. Rangel said.

The explanation was greeted with skepticism and surprise by some people in his district, where Spanish is the primary language in nearly half the households and even Mr. Rangel’s own Congressional Web site can be instantly translated to Spanish with just two clicks of a computer mouse.

The congressman brushed aside calls that he step down as chairman of the powerful House Ways and Means Committee, and accused Republicans who have demanded that he do so of trying to exploit his financial missteps.