WASHINGTON - ROBERT McNamara, the US secretary of defence whose broad career as an industry leader and a global financial aid revolutionary was overshadowed by his role as key architect of the Vietnam war, died on Monday aged 93, The Washington Post reported.

From 1961 to 1968, McNamara oversaw the escalation of US combat efforts in the highly divisive Vietnam war that became known as one of the biggest military blunders in US history - and a war McNamara himself came to describe as 'terribly wrong.'

Brilliant - arrogant, some would say - certain of himself and a whirlwind of energy, McNamara was a key member of president John F Kennedy's cabinet, a team famously described as 'The Best and the Brightest' in author David Halberstam's seminal book on the Vietnam war.

But in later years McNamara came to regret his Vietnam role, although he remained silent until the publication of his controversial 1995 memoirs

'In Retrospect: The Tragedies and Lessons of Vietnam.'

Top US officials 'who participated in the decisions on Vietnam acted according to what we thought were the principles and traditions of this nation,' McNamara wrote.

'We made our decisions in light of those values. Yet we were wrong, terribly wrong. We owe it to future generations to explain why.'

But his term as defence secretary did not start out that way, when Kennedy asked McNamara, then 44, to be his defence secretary soon after the young president was elected.

'I don't object to its being called McNamara's war,' he wrote of Vietnam in 1964. 'I think it is a very important war and I am pleased to be identified with it and do whatever I can to win it.'

Under McNamara's watch the US military role in Vietnam escalated from a few hundred Americans advising South Vietnam's military to some 17,000 soldiers by 1964.

And US involvement in the war escalated even more dramatically following the Gulf of Tonkin incident that year, in which, based on suspect intelligence reports, the US alleged North Vietnamese torpedo boats had fired on two US destroyers.

President Lyndon B Johnson - who took over when Kennedy was assassinated in 1963 - ordered retaliatory air strikes on North Vietnam, and by mid-1968 the number of US soldiers sent to fight in Vietnam had risen to 535,000. -- AFP