Speaking amid mounting concern over hospital delays, he said the government was working on freeing up beds.
He said this would relieve pressure in A&Es and on ambulance services.
It comes as a woman who waited 25 hours to be seen at an emergency department told the BBC it was "like a war movie".
Mr Barclay said people with conditions like heart disease had been reluctant to come forward for support at times during the pandemic - and this was a major factor in the demands now being seen.
He acknowledged the NHS was facing huge challenges, but said the government was providing extra funding to help.
This includes a £500m winter fund that has been set up to help hospitals discharge patients who are medically fit to leave but cannot because of a lack of support available in the community.
And he added: "We are so focused on getting people out of hospital who do not need to be there."
Labour criticised the government's management of the health service, while the Liberal Democrats called for Parliament to be recalled early.
MPs are due back at Westminster next Monday, following their Christmas break.
Prof Phil Banfield, who chairs the British Medical Association, which represents doctors, called on the government to "step up and take immediate action".
The situation was "intolerable and unsustainable", he said, with the NHS's survival on a knife edge and patients needlessly dying because of a political choice.
Richard Webber, of the College of Paramedics, said the current situation was the worst in his 30-year career.
Delays were causing patients "significant harm", he said, with ambulance services now struggling to find available crews for cardiac arrests - the highest category of emergency call.
"I've never known anything like it," Mr Webber said.Meanwhile, the UK Health Security Agency (UKHSA) has reiterated the importance of people wearing masks if they are ill and need to go out.
The UKHSA has also asked parents to keep children off school if they have a fever.