On the lack of sprinklers in Grenfell Tower, and other buildings, he said: "My understanding is that the best expert advice is that retrofitting sprinklers may not always be the best technical way of ensuring fire safety in a building".
"I have always said I will be accurate about what I know, so the next figure of those presumed dead and missing will be released tomorrow, Monday 19 June".
The job's contractor has said the work met all fire standards.
On Wednesday last week, a horrific fire ripped through a 24-storey residential tower in west London.
Cundy says the new number may change as investigation continues.
She says she will receive daily reports from the stricken neighbourhood, where hundreds of people have been displaced. There is also a real possibility that there may be people in the building that no one knows are missing.
In this photo released by the Metropolitan Police on Sunday, June 18, 2017, a firefighter stands outside of the Grenfell Tower after fire engulfed the 24-storey building, in London.
The news came as the Government announced those left homeless by the fire will be given at least £5,500 from an emergency fund.
Cundy added that authorities are investigating whether any crimes had been committed in the fire.
"There is a feeling from the community that they've been treated badly because some of them are poor", Khan said after a visit to a church near the burnt-out social housing block to attend a service which remembered victims of Wednesday's tragedy.
Mr Paget-Brown sidestepped questions over whether he felt guilty about the tragedy, telling BBC Radio 4's The World At One: "I feel bad about the whole position we find ourselves in". "The work to search the building is challenging, but naturally could never be done quickly enough for those now having to live with the uncertainty of knowing where their loved ones are".
His remarks came as Nick Paget-Brown, the Tory leader of Kensington and Chelsea council, insisted officials were on the ground "very soon" after the fire broke out following criticism from prime minister Theresa May, who said the support given to residents was "not good enough".
Appearing on the BBC's Andrew Marr Show, Mr Hammond said: "My understanding is the cladding in question, this flammable cladding which is banned in Europe and the United States, is also banned here".
The company behind the renovation also reportedly used banned, flammable cladding on the building's exterior to cut costs and make it more aesthetically attractive for neighbors in the Kensington and Chelsea borough, one of the UK's richest areas.
Aluminium composite panels are used to add insulation and to make a building more attractive, and consist of two metal panels sandwiching an inner material such as polyethylene, which was reportedly the case at Grenfell Tower. The BBC understands the death toll could rise to about 70 people in total.
The gutted tower block after firefighters had successfully fought the blaze.