As recently as Wednesday, his wife Susan denied her husband was in a critical condition, telling reporters, "Barry and God will decide when it's his time, and you can imagine who will have the last word." He had suffered a lengthy illness.

His funeral will be held on Wednesday at the Grady Gammage auditorium on the campus of Arizona State University.

Goldwater in 1995, aged 86

The former Arizona senator was widely regarded as the founder of the modern American Right.

In 1964 he ran a controversial campaign as the Republican presidential candidate, with the famous quotation that extremism in the defence of liberty was no vice, and moderation in the pursuit of justice was no virtue.

Although he was trounced by Lyndon Johnson, his campaign has been seen as paving the way for Ronald Reagan's rise to prominence.

In 1974, he was one of a handful of Republican leaders who went to the White House and bluntly informed Nixon that he would be impeached if he did not resign.

He retired from the Senate in 1986 after more than 30 years in office.

President Clinton: Goldwater "a great patriot and a truly fine human being"

President Bill Clinton led the nation in mourning the political figure with whom he often disagreed but whose advice he often sought.

Before a White House ceremony, Clinton referred to Goldwater as "truly an American original.

Tough talker

Barry Goldwater was known for his blunt assessments of his fellow politicians.

When former President Reagan said he didn't know about the diversion of Iranian arms profits to the Nicaraguan contras, Mr Goldwater branded him "either a liar or incompetent."

And the senator declared that Jerry Falwell, leader of the Christian right, deserved "a boot ...right in the ass" for attempting to foist his religious values upon the Republican political agenda.

Marriage at 83

After retiring from politics in 1987, Mr Goldwater surprised almost everyone in January 1992 when, at the age of 83, he announced that he was getting married.