Urgent fire testing will continue as the number of buildings failing safety standards rises in the wake of the Grenfell blaze.
The manufacturer of the panels used on the tower in west London has stopped global sales of the material for high-rise buildings.
Flammable cladding has been found on 75 tower blocks across 26 local authority areas, leading to calls for councils to urgently send samples for testing.
The so-called combustibility test has been failed by every building examined so far, Communities and Local Government Secretary Sajid Javid said.
Describing the Grenfell Tower fire as "a catastrophic failure", he announced the formation of an independent expert advisory panel to advise the Government on any immediate steps that need to be taken on fire safety.
He also revealed the Government had pledged £1 million to boost the work done by charities to support those in need since the deadly blaze.
The scope of the forthcoming public inquiry into the fire is expected to widen, examining the apparent widespread use of cladding.
It is not clear at this stage how many buildings could be affected.
Hospitals and schools are being tested to make sure they are not encased in combustible cladding, and Mr Javid said 15 buildings "across the wider government estate" require further investigation.
Mr Javid admitted multiple fire safety inspection failures had been discovered in tower blocks which were evacuated last week in Camden.
He said "literally hundreds of fire doors were missing" from high-rises there, as he outlined other failures including inaccessible stairways and breaches of internal walls.
Grading the material on a scale of fire-resistance, the assessment determines whether the material meets building regulations.
He said: "The fact that all samples so far have failed underlines the value of the testing programme and the vital importance of submitting samples urgently."
He added: "I am concerned about the speed at which samples are being submitted.
"I would urge all landlords to submit their samples immediately."
One Grenfell residents' group, part of the Justice4Grenfell campaign, welcomed the public inquiry but warned the voices of locals must be heard.
In an open letter to Prime Minister Theresa May and Home Secretary Amber Rudd, it demanded immediate funding for legal advice for bereaved families and survivors.
It added: "The investigation must leave no stone unturned. It must identify each and every individual and organisation who must bear responsibility and accountability for this tragedy and the mishandling of the aftermath.
"There must be swift recommendations to ensure there can be no chance of a repeat of this disaster elsewhere;
"Bereaved families and survivors will require time to recover and grieve, not least in view of the paucity of support they have been afforded by the state and its agencies in the immediate aftermath."
Earlier, the Prime Minister's official spokesman said questions over why the material was used on tower blocks nationwide despite breaching fire safety rules would probably be scrutinised.
"It is clearly a huge concern that this is the case," the spokesman told reporters.
Downing Street said the Department of Health and Department for Education would oversee the testing of schools and hospitals.
Schools and authorities responsible for schools have been contacted across the country and ordered to carry out checks on their buildings.
They have been told any concerns about materials used on school premises should be reported to the Government for investigation.
David Warner of London Funders, which is charged with co-ordinating the money, welcomed the additional £1 million.
He said: "We are delighted that the DCLG (Department for Communities and Local Government) has responded with vital funds to provide immediate support to community groups in Kensington and Chelsea who are supporting those directly affected by the Grenfell Fire.
"London Funders, along with a consortium of trusts and foundations, is making sure the money gets to those groups who can best use it as quickly as possible.
"We have now put in place the processes to make that happen."