WASHINGTON: As US President George W. Bush's national security adviser and then Secretary of State, Dr Condoleezza Rice has long been seen as the toughest woman in American politics.

But a new book reveals that she was so fazed by former defence secretary Donald Rumsfeld that she burst into tears at a meeting, The Telegraph reported.

The floodgates opened for the then national security adviser in February 2004, as the Bush administration was wrestling with Iraq and the legal status of detainees at the Guantanamo Bay detention camp.

A new biography of Vice-President Dick Cheney recounts how he and Mr Rumsfeld conspired to delay the military tribunals which the President had ordered to be set up to try the terrorist suspects.

Dr Rice tried repeatedly to organise a meeting with the most senior figures in the government to discuss the tribunals, but Mr Rumsfeld twice refused to attend.

The book said that upon Mr Rumsfeld's absence from a second meeting, 'something happened to Rice's face, control melting away. Her eyes welled up and her next words caught in her throat...

''She started to cry,' said one of them. 'And she said - I can't remember the exact words because I was so shaken - something like: 'We will talk about this again,' and she turned and walked quickly out of the door.''

But Dr Rice had the last laugh. Mr Rumsfeld was fired in 2006.