WASHINGTON — Rep. Charles Rangel of Harlem is resisting calls that he resign as chairman of a powerful House tax-writing committee, but he acknowledged yesterday that his failure to pay taxes on income from a vacation home in the Dominican Republic was “irresponsible” and that he had not lived up to the standards of his high office.

Mr. Rangel, head of the House Ways and Means Committee, vowed to pay thousands of dollars in back taxes to the city, state, and federal governments on $75,000 in unreported income from the property, and he pledged to abide by the decisions of the House Ethics Committee, which, at his request, is launching three separate inquiries into his personal finances and political activity.

The longtime New York congressman scoffed at the demand from House Republican leaders that he relinquish his committee chairmanship while the investigations are ongoing.

“I really don’t believe that making mistakes means you have to give up your career,” Mr. Rangel said. He added later: “I personally feel I have done nothing morally wrong.”

He cast doubt on the sincerity of the Republican leader, Rep. John Boehner of Ohio, whom Mr. Rangel suggested was bowing to political pressure from within his party to call for Mr. Rangel to step down.

Mr. Rangel’s lawyer, Lanny Davis, estimated that he owed in the area of $10,000 in total taxes for the years 2004 through 2006, but he cautioned that Mr. Rangel’s lawyers and accountant were still seeking and combing through documents for other years and that the figure could rise.

The property in question is a resort villa in an area of the Dominican Republic known as Punta Cana. Mr. Rangel purchased the house in 1988 for $82,750, making a down payment of $28,900 and securing a 20-year mortgage to cover the rest. Under an arrangement with the resort’s owners, he did not make payments on the mortgage, which was paid off from income earned through rentals of the house. Mr. Rangel said members of Congress and other guests also stayed at the villa, but his office was unable to provide a list yesterday. Mr. Rangel said he rarely used the home himself and never stayed there for more than four days in any one year.

Mr. Rangel, 78, said he was unaware he was earning income on the property because the resort owners did not send out statements to investors for most years. When he did inquire about the property, he said, “cultural and language barriers” got in the way.

“Every time I thought I was getting through, they started speaking Spanish,” Mr. Rangel told reporters.

Through the course of a press conference that lasted more than an hour, Mr. Rangel voiced contrition for his mistakes while also using his trademark wit to deflect questions about the political implications of the disclosure that he, the nation’s top tax writer, had stumbled on paying his own taxes. All the while, he projected an air of confidence about his predicament, cognizant of his deep support within the Democratic Party leadership and that he faces little opposition in his home district.

“I’m a lucky old son of a gun. Ain’t nothing going to stop me from getting back here next year,” he said, adding that the situation would be much worse for a younger lawmaker, of either party, who would have a harder time mounting a defense in the face of swirling allegations and negative news reports.

At the same time, he said he had been “irresponsible” in his ignorance of the tax and income implications of his beach house, and he acknowledged that as a member of Congress and chairman of the Ways and Means Committee, he was subject to “a higher standard” of propriety. Asked if he had met that standard, he replied: “Of course not.”

Mr. Rangel has also asked the ethics panel to investigate his leasing of four rent-stabilized apartments in a single Harlem building, including one he used as a campaign office. And the committee is expected to probe his use of congressional stationery to solicit support for a City College academic center named in his honor.

Republicans have seized on the cloud surrounding Mr. Rangel as a campaign issue, and there are signs the inquiries have undercut his reputation on Capitol Hill. Yesterday, the watchdog group Citizens for Responsibility and Ethics in Washington added him to its list of the 20 “most corrupt” members in Congress, a designation that Mr. Rangel called “sad and unfair.”

Hours after his morning news conference, Mr. Rangel took to the House floor to defend himself, and he wound up in a heated exchange with Mr. Boehner after suggesting the Republican leader was pressured to call for his resignation. “It pains me to do what I have to do on behalf of my colleagues,” Mr. Boehner said, calling Mr. Rangel a “friend.” While saying he hadn’t “convicted” Mr. Rangel, he stuck by his demand. “Just because he is my friend doesn’t mean I can excuse him from the rules of the House or the laws of the land,” Mr. Boehner said.