Health Secretary Wes Streeting has said there is a “risk of disruption” in the NHS as he attempts to overhaul the service and reduce waste, but has promised long-term improvements.

On Thursday, Streeting announced NHS England, a public administrative body, would be scrapped to save money and give ministers more control of health services.

The Labour government expects the move will take two years and save hundreds of millions of pounds that can be spent on frontline NHS services.

Appearing on the BBC’s Sunday with Laura Kuenssberg programme, Streeting defended the reforms but admitted there would be challenges.

When asked about the impact on patient care, he said: “Of course there are always up-front costs. And yes there is always a risk of disruption.”

Streeting said former health secretaries had “not been prepared to take on those sorts of challenges” and argued NHS England “was set up to shield politicians like me from responsibility”.

He said: “I’ve seen waste, inefficiency and duplication. So of course we should go after that.”

When asked for a second time if patient care would be disrupted by the government’s reorganisation of the NHS, Streeting promised to deliver improvements and said waiting lists for treatment had already been falling.

The government said its main reasons for abolishing NHS England were to “cut bureaucracy” and reform how health services operate.

It dubbed NHS England “the world’s largest quango” – the term used to describe publicly funded organisations at arm’s length from the government

Currently, NHS England oversees the health service, working with government to agree funding and priorities, as well as monitoring the performance of local NHS services.

Under the changes, the organisation will be brought into the Department of Health and Social Care (DHSC), which is headed by Streeting.

The reforms will not impact anyone’s access to the NHS, with the health service remaining free at the point of use.

The government said it expected around half of the jobs at NHS England and DHSC to go – around 9,000 administrative roles.

The chairman of NHS England, Richard Meddings, said he did not disagree with the abolishing of the organisation, in his first interview since the changes were announced.

But speaking to the BBC, he said the buck will now stop with ministers, saying: “There will no longer be a separate vehicle that can be pointed [at] to say that’s what got it wrong.”

Writing in the Telegraph, Streeting suggested scrapping NHS England was “the beginning, not the end” and said he would continue “slashing bloated bureaucracy”.

The health secretary tasked Penny Dash, who was made chairman of NHS England at the start of this month, with carrying out a review of bureaucracy.

Some of the organisations overseen by the Department for Health include Care Quality Commission, the UK Health Security Agency and the National Institute for Health and Care Excellence.

Beneath those is a patchwork of smaller public bodies on a regional and local level.

Speaking to the BBC, Streeting would not be drawn on which bureaucratic NHS organisations he would consider axing, but suggested there was “an overregulation” of NHS services.

He said NHS frontline leaders have told him “they are often receiving a barrage of commands – sometimes contradictory and competing demands – from the Department for Health, from NHS England and from the wide range of regulators in this space”.

He said simplification would set the NHS up to succeed and he was “going after the bureaucracy, not the people who work in it”.

He added: “Of course, I can’t sugar coat the fact that there will be a significant number of job losses and we will want to make sure we are treating people fairly, supporting them properly through that process.”

The Conservatives have welcomed the move to bring the management of the health service back under ministerial control, but warned Labour “cannot hide if things go wrong”.

The Liberal Democrats said the government should ensure that scrapping NHS England does not “have negative impacts on the quality of care for patients” and urged ministers to complete a review of social care.