Jeremy Hunt has said he is "not going to budge" on the A&E waiting time target - despite the health service repeatedly missing the goal in recent months.
The Health Secretary said the four hour A&E waiting time target is "incredibly important" as he told health experts that he did not want to "let go of that achievement".
A&E departments are now routinely missing the national target to deal with 95% of patients within four hours.
Major type 1 A&E departments - those that are located in hospitals - have performed the worst, with only 87.9% of patients admitted, discharged or transferred within the timeframe during 2015/16.
Mr Hunt told the King's Fund annual conference in London: "Although there are huge pressures and we are not hitting a number of very important access targets for A&E or the 18 week wait for elective care, we are not going to budge on the importance of maintaining those standards across the NHS because I think it is an incredibly important thing that we as a system have achieved.
"To promise to the people of this country that we will get you your emergency care in four hours, that you shouldn't have to wait more than 18 weeks for your elective care, is a really important achievement and whatever the pressures we do not want to let go of that achievement."
He added: "On the access targets, let's remember there are only three other countries in the world that have national A&E targets - Canada, Australia and New Zealand - and I think we are doing better than them and we are still seeing nine in 10 within the four hours.
"But sometimes we feel we are not doing well because we are one of the only systems in the world that collects that data and publishes on a national basis.
"I want to pay tribute to the people who work in A&E, who are working under huge pressures that we have.
"And I want to reassure them that we are absolutely committed to holding the line and that we do return to the kind of performance and flow that they want for their patients, we want that as well."
Earlier this month, a powerful group of MPs warned that poor performance in A&E has "become the norm" for some NHS trusts.
A report from the Commons Health Committee warned the NHS could face a "substantially more difficult" winter this year than last, with increasing demand for services, trusts suffering due to too-few staff and a widespread inability to move out patients who are medically fit to be discharged.
In July NHS officials in England announced that hospital trusts will no longer be fined for missing key targets on waiting times and cancer as part of a bid to improve finances.