Ron Ziegler, the combative former press secretary to President Nixon who famously called the Watergate break-in a "third-rate burglary," died Monday of a heart attack, his wife said. He was 63.

Ziegler died at his home in Coronado, a suburb of San Diego, his wife, Nancy, told The Associated Press.

Ziegler functioned as the point man for an administration under fire, the president's strident defender until the public release of the Watergate tapes made it clear that Nixon and his top aides had engaged in a vast cover-up.

As Washington Post reporters Bob Woodward and Carl Bernstein tied the scandal to top officials in the Nixon administration, Ziegler routinely dismissed their reports as inaccurate.

The first denials came two days after the break-in.

"Certain elements may try to stretch this beyond what it is," Ziegler said of the June 17, 1972, burglary of the Democratic National Committee headquarters that would eventually lead to Nixon's resignation.

The press secretary publicly apologized to Woodward, Bernstein and their newspaper the day after the April 30, 1973, resignations of White House counsel John Dean and Nixon aides John Ehrlichman and H.R. Haldeman.

"I would apologize to the Post, and I would apologize to Mr. Woodward and Mr. Bernstein. ... We would all have to say that mistakes were made in terms of comments. I was overenthusiastic in my comments about the Post, particularly if you look at them in the context of developments that have taken place," he said at the time. "When we are wrong, we are wrong, as we were in that case."

He started to add, "But... ," and was cut off by a reporter who said, "Now, don't take it back, Ron."

In a Nov. 12, 1973, news conference, it was Ziegler who announced that Nixon would give up unsubpoenaed White House recordings and portions of his diary.

In a 1981 interview with The Washington Post, Ziegler defended his use of the phrase "third-rate burglary," and said he hadn't known of the cover-up.

"I was right," he said. "It was a third-rate burglary. Who knew it was going to be anything more than that?"

Dean, who helped expose the scandal, said in an e-book published last year on Salon.com that Ziegler, despite his complaints about Woodward and Bernstein's reporting, was one of the people who may have been Deep Throat, the mysterious, chain-smoking source who gave Woodward crucial information in secret late-night meetings.

Woodward has said he will not reveal Deep Throat's identity until that person's death. As recently as last year, he said Deep Throat was still alive.

Ziegler said he believed Deep Throat was a composite of several sources, which Woodward has denied. In All the President's Men, Woodward and Bernstein said Deep Throat did a mean imitation of Ziegler.

Dean said his admiration for Ziegler's honesty was one of the reasons he believes the former press secretary might have been Deep Throat.

"He had this remarkable memory, which served him well," Dean said. "He also had an impossible job after Haldeman and Erlichman departed. He became Nixon's sounding board and nothing could have been more difficult in those dark days. I always wished he had written a book. It would have been a wonderful insight."

As spokesman for a much-maligned administration, Ziegler was often unpopular with the public and the press in the early 1970s. His friends said he was tarnished unfairly because of his loyalty to Nixon.

"Deep down he was a wonderful person," Gerald Warren, a former deputy press secretary under Presidents Nixon and Ford said Monday night. "I think he was placed in an awkward position as a young man. ... It wasn't easy for him, but he did his best and he was very loyal.

"I don't think he ever showed the great promise that he had," Warren said. "I wish that he had been able to tell his story to the world."

Veteran GOP consultant Ken Khachigian, who served as a Nixon speech writer, called Ziegler "an exceptionally capable press secretary" who spoke for an administration faced with Watergate, the Vietnam War and the release of the Pentagon Papers, the top secret study on U.S. involvement in Vietnam.

"It was a tough time to be a press secretary," said Khachigian, 58, who now lives in Southern California. "All of us who lived through those days had a lot of scar tissue."

Ziegler, who first worked with Nixon as a press aide on his unsuccessful campaign for California governor in 1962, stayed with the politician through fights with reporters -- and even his boss.

Nixon bristled when he saw Ziegler helping the news media too much. During one visit to New Orleans, he shoved Ziegler and snapped, "I don't want any press with me, and you take care of it."

He stayed with the president even after Nixon's fall from grace.

"I was the only one on that plane to San Clemente with Nixon when power changed hands," he said. "I was there with Nixon in exile. ... I'm proud of what I did as press secretary. I don't feel the need to apologize. There are some things, however, I would have done differently.

Asked for examples, he said, "Well, I don't want to go into that."

Ziegler said in the 1981 interview with the Post that he had never lied about Watergate: "It's necessary to fudge sometimes. You have to give political answers. You have to give non-answers. But I never walked out on that podium and lied."

Nixon's daughter, Tricia Nixon Cox, praised Ziegler for his loyalty to her father.

"Ron was a most capable and loyal public servant who served the White House and my father with distinction," she said. "He was a key participant in the great events of my father's administration, including the historic trips to China and the Soviet Union. Most of all he was an extraordinary friend of our family."

Ronald Louis Ziegler was born May 12, 1939, in Covington, Ky. He grew up in Cincinnati, then moved to California and enrolled at the University of Southern California. He also took a job at Disneyland as a guide on the Jungle Tour -- and later jokingly told the Post it was good experience for his political career.

When Nixon lost the gubernatorial election in 1962, Ziegler joined an advertising firm at the urging of Haldeman, who would become Nixon's chief of staff. When he joined Nixon's 1968 presidential campaign at 29, he became the youngest White House press secretary in history.

He held that title until 1974, when he was named an assistant to the president.

After leaving government service, he held a number of positions in the private sector, most recently as chief executive of the National Association of Chain Drug Stores from 1987. He retired in 1998.

Ziegler divided his time in recent years between Alexandria, Va., and Coronado, where he owned a condominium overlooking the ocean.

In addition to his wife, Ziegler is survived by his mother, Ruby Ziegler of Cincinnati; and two daughters, Cindy Charas of New Canann, Conn., and Laurie Albright of Denver.

He was to be cremated, with a memorial service planned for later this month in Washington.