Chancellor Kwasi Kwarteng has said he is "sticking to the growth plan" announced in his mini-budget.
He also rejected claims it had made people worse-off by contributing to a spike in mortgage rates across the UK.
The plans, announced on Friday, have led to market turmoil, and the Bank of England stepping in to prevent the collapse of some pension funds.
In a rare rebuke, the International Monetary Fund openly criticised the UK government over the plan.
However, Mr Kwarteng told reporters on Thursday his priorities were keeping to the plan and lowering energy bills.
Speaking trip to Northern England he said: "The mini budget was absolutely essential in resetting the debate around growth and focusing us on delivering much better growth outcomes for our people.
"Without growth you're not going to get the public services, you're not going to generate the income and the tax revenue to pay for the public services that we want to see."
He added that government's plan to limit energy energy bills for households and businesses would save people "thousands of pounds a year".
"We're very, very focused on making sure the cost of living pressures can be withstood by ordinary people right up and down this country," he said.
Since last Friday's mini-budget, the government has confirmed it has written to government departments asking them to make efficiency savings.
Asked if he would keep the previous government's promise to increase benefits next April in line with inflation, Mr Kwarteng said it was "premature" to come to decision on that.
However, he said the Prime Minister was committed to maintaining the triple lock on pensions.
This is the first time Mr Kwarteng has made a public comment on his min-budget since Sunday, when he hinted that there were more tax cuts to come.
Since the pound has touched a record low against the dollar and UK borrowing costs have soared, prompting the Bank of England to buy $65bn of government bonds in a bid to calm markets.
Mr Kwarteng's remarks came after Prime Minister Liz Truss spoke to a number of BBC radio stations on Thursday morning, where she insisted the tax cuts outlined in the mini-budget were the "right plan".
Prior to the mini budget, the Treasury had turned down an independent forecast of the impact of government's plans on the economy by the Office for Budget Responsibility (OBR). BBC economics editor Faisal Islam said this had made the market reaction to the plans worse.
The OBR said on Thursday that it had been asked by Mr Kwarteng to produce a first draft of its next economic forecasts by 7 October.