The NHS will get "whatever resources it needs" to cope with a coronavirus epidemic, Chancellor Rishi Sunak has said ahead of Wednesday's Budget.
He told the BBC's Andrew Marr Show "strong" economic foundations meant he could provide additional funding.
The chancellor also said he was looking at extra financial help for individuals and businesses if measures against the virus meant they were out of pocket.
On Sunday UK cases rose to 273, up from 209 on Saturday - the biggest rise yet.
It comes as Tesco said it had begun rationing essential food and household items as a result of coronavirus stockpiling.
In other developments, the UK Foreign Office is advising against "all but essential travel" to large parts of northern Italy after they were put in lockdown.
Mr Sunak has pledged to address the outbreak in his first Budget and said the impact of the virus on business "could be significant, but for a temporary period of time".
He said: "I can say absolutely, categorically, the NHS will get whatever resources it needs to get us through this crisis."
The government's medical advisers say the UK is still in the "containment" phase, but they expect to move to a "delay" phase soon, in which the focus is on trying to slow down the spread.
This phase could see the introduction of "social distancing" measures such as closing schools and urging people to work from home.
Mr Sunak said he was looking at temporary measures to support people who may be unable to go to work or businesses which may suffer as a result of the measures.
This could include ensuring benefits under universal credit and Employment and Support Allowance are available "quickly and effectively", waiving requirements for sick notes or in-person benefits interviews, and providing help for businesses with cashflow problems, he said.
"I'm keen to make sure when we get through the other side, we haven't lost these great small businesses permanently," he said.
'Very strange chills'
A man who became infected with coronavirus after returning from a skiing trip in northern Italy last weekend has told Radio 4's Broadcasting House of the "very strange chills" he experienced after developing symptoms.
He flew home from Innsbruck over the border in Austria to Manchester Airport.
He first experienced a dry cough after he and his wife self-quarantined in their home as a precaution, before "suddenly" developing a fever, a headache and a warm chest.
"And there were very strange chills that seemed to spread all around the surface of your body, very quickly, and then reverberate around - it's a very strange feeling," he said.
He was later confirmed to have the virus after being tested at a specialist coronavirus pod. His wife, however, tested negative - to both of their surprise.
The man said he was now "really well recovered" but would have to remain in self-quarantine until he was told by health professionals he could leave.
Listen to the full interview here.
With an epidemic potentially putting extraordinary pressures on the public and private sector, Mr Sunak was repeatedly asked whether he would stick to the government's fiscal rules.
He did not answer directly, but said he believed "very much in the importance of fiscal responsibility, about responsible management of our public finances" and added that "difficult decisions" by past chancellors meant he could respond to this crisis.
He declined to say whether government debt would be lower by the end of this parliament, if the government would borrow to fund day-to-day spending or whether he could guarantee to balance the budget within three years.
Mr Sunak's pledge to the NHS comes as the government outlined emergency legislation, which could be introduced to the Commons this month, to protect people's jobs if they volunteer to care for coronavirus patients.
The government says about three millon people currently volunteer in "a health, community health and social care setting".
'Massive national effort'
Under the proposed plan, the jobs of "skilled, experienced or qualified volunteers" would be protected for up to four weeks while they care for people with Covid-19, the illness caused by the coronavirus.
Ministers have also proposed the emergency registration of retired health professionals, and the new bill will aim to ensure their pensions are not negatively impacted by returning to work in the NHS.
Health Secretary Matt Hancock said the UK's response to a widespread outbreak required a "massive national effort" and these were "proportionate" measures.
"I want to ensure government is doing everything in its power to be ready to delay and mitigate this threat," he said.
Tom Dolphin, a doctor who is a member of the British Medical Association's governing council, told the BBC the measures could help to free up capacity in hospitals by allowing people to be discharged into social care.
But he said the health service was under-resourced and could still find itself having to make "difficult choices", postponing planned operations to cope with emergencies and epidemic cases.
Five hundred extra staff have also been recruited to work on the NHS 111 phone service, after calls increased by a third over the last week, compared with the same period a year ago.
Globally, the number of coronavirus cases has now passed 100,000, with 3,400 deaths.
In other developments:
- Italy has placed at least 16 million people in quarantine in the region of Lombardy and in 14 other provinces in the north and east of the country
- A group of 30 Britons and two Irish nationals were released from isolation at Arrowe Park Hospital in Wirral on Sunday after returning from coronavirus-hit cruise ship, the Diamond Princess
- Tesco has begun rationing essential food and household items as a result of customers stockpiling goods
- A student at Oxford University has tested positive, but the university said the risk to other students and staff was very low
- London Ambulance Service officials have considered telling paramedics they must be clean shaven to protect themselves from coronavirus
- About 70 people were trapped after a hotel being used as a coronavirus quarantine facility in the Chinese city of Quanzhou collapsed