The Grenfell Tower fire was a “preventable accident” caused by “years of neglect” by the local council and successive governments, Mayor of London Sadiq Khan has said.
After attending a service for victims, he called the fire a national disaster requiring a national response.
Kensington and Chelsea Council’s leader said officials had been working “around the clock” since Wednesday.
“No one local authority would be able to cope,” he added.
Nicholas Paget-Brown said there were “enormous challenges” facing his borough’s residents.
The government has sent in some of its staff to bolster the relief effort. They were spotted in high-visibility jackets in the area on Sunday afternoon.
The council has been widely criticised for its handling of the disaster, with residents complaining that officials had provided little support or information.
Mr Khan said: “People are angry, not simply at the poor response in the days afterwards from the council and the government, but at the years of neglect from the council.
“There’s a feeling that the council and government don’t understand their concerns and don’t care.”
He said the fire – which is thought to have killed at least 58 people – was the consequence of the “mistakes and neglect from the politicians – the council and the government”.
“People in this community are sick to death of platitudes from politicians,” he added.
Writing in the Observer on Sunday, Mr Khan suggested high-rise tower blocks dating from the 1960s and 1970s could be torn down in the wake of the fire, which he said may well be the “defining outcome of this tragedy”.
Police fear the number of the dead could increase. The BBC understands the death toll could rise to about 70 people in total.
Councils across London are now involved in the relief operation, with humanitarian assistance being provided by the west London borough of Ealing.
As part of the latest action from government, a team of civil servants has been embedded into the Kensington council office.
Other measures outlined by the prime minister, following a meeting with residents on Saturday, included more staff covering phone lines and ground staff wearing high-visibility clothing so they could be easily found.
Labour leader Jeremy Corbyn told ITV’s Peston on Sunday that the council had seemed to “lack the resources to deal with a crisis of this magnitude”, despite being the country’s “wealthiest borough”.