LAS VEGAS - Nevada Republican John Ensign apologized yesterday for having an affair with a member of his campaign staff more than a year ago and said he remains "deeply committed" to his service in the U.S. Senate.

Ensign called the affair "absolutely the worst thing that I have ever done in my life," and said he and his wife sought counseling and reconciled.

He didn't identify the staffer or her husband, and took no questions after issuing his statement.

He called the woman and her husband "close friends," and said that close relationship at a difficult time in his marriage "led me to my inappropriate behavior."

Ensign told the Associated Press in a statement, "I deeply regret and am very sorry for my actions."

An aide in Ensign's office said the affair took place between December 2007 and August 2008 with a campaign staffer who was married to an employee in Ensign's Senate office. Neither has worked for the senator since May 2008. The aide spoke on condition of anonymity because he was not authorized to discuss the developments.

"I know that I have deeply hurt and disappointed my wife, my children, my family, my friends, my staff and the people of Nevada who believed in me not just as a legislator but as a person," Ensign said.

Ensign's wife, Darlene, also released a statement about the affair.

"Since we found out last year we have worked through the situation and we have come to a reconciliation," she said. "This has been difficult on both families. With the help of our family and close friends our marriage has become stronger."

Ensign was first elected to the Senate in 2000 and has been an influential conservative voice within that chamber. Last year, his GOP colleagues picked him to serve as chairman of the Republican Policy Committee, moving him to the No. 4 position in leadership. The committee coordinates the GOP's legislative efforts in the Senate. Previously, Ensign ran the Republican Senate campaign operations.

Last month, Ensign traveled to Iowa for a speech organized by a conservative advocacy group, sparking speculation that he had an interest in possibly running for president. Aides said the visit was about staking out a leadership position within the GOP. *