WASHINGTON - US ATTORNEY General Michael Mukasey was 'conscious, conversant and alert' at a local Washington hospital after collapsing while delivering a national security speech at a hotel, the US Justice Department said late on Thursday.

'His vital statistics are strong and he is in good spirits,' department spokesman Peter Carr said in a statement.

'The doctors will keep him overnight for further observations.'

Mr Mukasey, the top US law enforcement and legal official, was rushed to George Washington University Medical Center in Washington after he collapsed.

President George W. Bush was told of Mr Mukasey's condition and would be kept apprised of any developments, the White House said.

'The president was informed about the attorney general and he has him in his thoughts and hopes that he will have a speedy recovery and be back at work soon,' White House spokesman Scott Stanzel said.

One witness said Mr Mukasey, 67, collapsed suddenly and unexpectedly, near the end of his speech defending the Bush administration's war-on-terrorism policies to a conservative legal group.

'It was very somber,' said the person, who asked not to be identified, of the atmosphere in the room after Mr Mukasey collapsed.

The individual said Mr Mukasey's security detail quickly moved to handle the situation after his collapse and called for emergency personnel, who then arrived, attended to him and took him to the hospital.

Mr Mukasey, a former federal judge, has been attorney general for about a year, dealing with such issues as terrorism, crime and corporate wrongdoing stemming from the financial crisis.

He is expected to leave office in January as part of the changeover to the incoming Obama administration.

His speech was to the annual dinner in Washington of the Federalist Society, held in the grand ballroom at the Marriott Wardman Park Hotel. -- REUTERS