The education secretary has said he cannot give a date for when English schools will reopen, four weeks after they were shut to curb the spread of coronavirus.
At the government's daily briefing, Gavin Williamson said there were "no plans" to open schools over summer.
He said five "tests" must be met before schools could reopen, including a fall in infections and the daily death rate.
It follows a Sunday Times report that said schools could reopen on 11 May.
UK schools were closed to all but vulnerable children and those of key workers on 20 March.
Mr Williamson said: "People are anxious to know when we're going to relax restrictions, when schools are likely to be fully back and open again.
"Of course, I want nothing more than to see schools back, get them back to normal, make sure the children are sat around, learning, and experiencing the joy of being at school. But I can't give you a date."
Decisions on education are devolved in Scotland, Wales, and Northern Ireland.
He said five "tests" must be met before education establishments could reopen including a fall in the daily death rate from coronavirus, reliable data showing the rate of infection was decreasing to "manageable levels", and being confident any adjustments would not risk a second peak.
Addressing children directly, Mr Williamson said: "I wanted to say to you how sorry I am that you've had your education disrupted in this way.
"I want you to know that you are such an important part of this fight too, and I cannot thank you enough for all that you are doing."
The education secretary also said he recognised how care leavers, and those about to leave care, were "really vulnerable", adding that he had asked local authorities "to ensure no-one has to leave care during this difficult time".
Mr Williamson said a further £1.6m had been given to the NSPCC charity to help it provide advice to children and adults.
From Monday, he said, a series of 180 online lessons per week will be made available for pupils from reception through to Year 10.
The online lessons, which have been prepared by teachers and education organisations, will be available under the label of Oak National Academy.
Laptops will be provided for some disadvantaged children in England, including pupils taking GCSEs next year, children with a social worker, or those leaving care.
There is no specified number of laptops available, or set budget, and it will be up to schools or local authorities to decide who needs help with access to a computer.
Mr Williamson also promised free 4G routers to help families connect to the internet.
No decision is imminent on re-opening schools in England.
That was the clearest message from Education Secretary Gavin Williamson.
Before even setting a date he said five tests would need to be met. Once that had happened, parents and teachers would need "proper notice" before re-opening schools.
None of that sounded like any change in the next few weeks.
Teachers' unions have described social distancing in school as "impossible" - and head teachers have described pressure for an early return as "irresponsible".
Mr Williamson's strong notes of caution suggest any return this half-term is unlikely - which would mean attention might shift to the second half of the term - so not before 1 June at the earliest.
The focus instead will be on helping pupils to learn online at home, because that is where they will be for the foreseeable future.
Another 596 people in the UK have died in UK hospitals with coronavirus, taking the total number of hospital deaths to 16,060.
Speaking at the No 10 briefing, England's deputy chief medical officer Dr Jenny Harries said the lower number of deaths recorded on Sunday was "very good news" but cautioned against jumping to conclusions.
She declined to say whether the UK had "passed the peak" of the virus, adding: "If we don't keep doing the social distancing, we will create a second peak and we definitely won't be past it.
"But I do think things look to be heading in the right direction."
BBC health correspondent Nick Triggle said while Sunday's figure was the lowest for nearly two weeks, figures often dropped at weekends because of delays reporting and recording deaths.
Addressing ongoing criticism and concern over the lack of personal protective equipment (PPE) for health and care workers, the education secretary said an "enormous strain" had been put on the system.
Mr Williamson said 400,000 gowns from Turkey which had been expected to arrive on Sunday had been delayed but were due to be flown in to the UK on Monday.
There have been warnings that some hospitals' intensive care units could run out of gowns this weekend.
Asked by the BBC why UK suppliers offering to make PPE had not been contacted, Mr Williamson said the government hoped to speak to them within "the next 24 hours".
He added that "every resource of government" had been deployed to expand supplies of PPE and ventilators.
In other developments:
- Cabinet Office minister Michael Gove has said the government will make a "balanced judgement" when deciding how to relax the coronavirus lockdown
- Asda is cancelling a quarter of orders with clothing suppliers and has said it would only pay for part of such cancelled orders
- New data from the National Care Forum has added to growing evidence that the number of deaths linked to coronavirus in UK care homes may be far higher than those recorded so far
- Construction of Scotland's temporary coronavirus hospital, NHS Louisa Jordan, has been completed. The £43m facility at the Scottish Events Campus (SEC) in Glasgow will be ready to receive Covid-19 patients from Monday, if required.
- Tributes have been paid to two workers serving the health care sector in Swansea who have died with Covid-19
- Britons in Bangladesh will be able to fly home this week, with up to 850 seats available on four repatriation flights
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