Britain's prime minister Theresa May has rejected claims that the NHS is in "crisis" saying the health service is better prepared ''than ever before''.
Mrs May made the comments after it was revealed tens of thousands of non-urgent NHS operations could be deferred until January 31 due to winter pressures.
Hospitals have also been told to delay routine outpatient appointments and to concentrate on emergency care.
NHS England's acute care director said hospitals were being given the "time and space" to manage January pressures.
Mrs May, answering questions after visiting homeowners who had benefited from stamp duty reforms in Wokingham, paid tribute to NHS staff and pledged operations would be rescheduled ''as soon as possible''.
Mrs May was asked by a reporter: ''If this is not a crisis in the NHS this winter, how would you classify it?''
She said: ''Can I say a huge thank you to NHS staff for their hard work, they work hard and do a fantastic job for us day in and day out all year round, but obviously there are extra pressures in winter.
''They're doing a fantastic job and their dedication is ensuring that people are getting treatment that they need."
She added: ''The NHS has been better prepared for this winter than ever before, we have put extra funding in.
''There are more beds available across the system, we've reduced the number of delayed discharges of elderly people who would otherwise have been in NHS beds rather than in social care.
''But I recognise for those people that have had their operations postponed this is disappointing, it's frustrating
''We will ensure that those operations are put back as soon as possible and once again I say that NHS staff are doing a fantastic job.''
Labour's shadow health secretary Jonathan Ashworth said: "Yet again Theresa May reveals how entirely out of touch she is.
"Next, she will be trying to lecture patients that 'nothing has changed' for patients.
"The reality is we see hospitals at full capacity, ambulances backed up, cancelled operations and patients waiting for hours on trolleys.
"Instead of burying her head in the sand, Theresa May needs to explain why she has allowed underfunding and cuts to health and social care to continue.
"As Tory MP Sarah Wollaston said this morning, the government needs to get a grip."
