The US is the best place for a business to invest, the boss of one of the UK’s biggest pharmaceutical companies has said.

Dame Emma Walmsley, chief executive of vaccines and medicines giant GSK, said it will invest $30bn (£23bn) in the US by 2030.

It comes as other major drug makers have pulled UK projects worth billions after years of frustration on NHS drug budgets and pressure from President Donald Trump to set up production in the US.

However Dame Emma, who will leave GSK in January after eight years in charge, welcomed a new deal which will see the NHS pay more to help secure zero tariffs on shipping UK pharmaceuticals to America.

Speaking to the BBC from the firm’s central London headquarters, Dame Emma said she would not “shy away” from GSK’s investment plans for the US, where it makes more than half of its turnover.

The US is “still the leading market in the world in terms of the launches of new drugs and vaccines,” she said. And alongside China, it was “the best market in the world to do business development,” she added.

GSK’s latest stateside investment drive followed US pharmaceutical company Merck – which is called MSD in Europe – scrapping a planned £1bn expansion of its UK operations.

UK drug maker AstraZeneca has also announced it is pausing a planned £200m investment in a Cambridge research facility while ploughing tens of billions of dollars into the US.

Other drug companies have also said there is little appetite to invest in the UK which successive governments have insisted is a life sciences superpower.

Despite the challenges facing Britain’s pharmaceuticals industry, Dame Emma said the deal to scrap tariffs on UK drug shipments to the US was “a step in the right direction” for Britain.

The deal means the UK will pay more for medicines through the NHS – in return for a guarantee that US import taxes on pharmaceuticals made in the UK will remain at zero for three years.

Dame Emma said it was a welcome reversal of a long term decline in the portion of the NHS budget spent on medicines compared to other countries’ health systems.

The move, she said, would encourage the kind of innovation that supports ground breaking new medicines like GSK’s new asthma drug which can be taken twice a year and could slash hospital admissions by 70% for serious asthma sufferers.

GSK hopes the new treatment will be approved for use by the NHS within weeks.

Asked about the health of the country, she said there were “social demographic root causes” for its decline.

She said UK health outcomes varied widely depending on where you live “you can probably get a 10 or 15-year difference in lifespan prospects depending on which postcode you’re in.”

Dame Emma pointed to British diets and a lack of education around nutrition as part of the problem.

“I think there’s no question that the food system is fundamentally something we need to look at harder,” she said.

Dame Emma also opened up about the differences she has experienced between the NHS and the private healthcare system in the US, having given birth in London, Paris and twice in New York.

“Both the experience of childbirth and all the follow up that happens afterwards are very, very different,” she said. “Anything from the advice you’re given…the frequency with which you are expected to be visited, how long you are in hospital and what kind of follow-up advice.”

Dame Emma said what matters is the balance of price, access and outcomes, and that the NHS still has “work to do” on getting the balance right.

Dame Emma, who also sits on the board of Microsoft, said the world was on the cusp of major advances in health science thanks in part to advances in AI which promise to accelerate innovation

“90 % of the projects in our industry don’t work, they take a decade and cost billions, getting to a place where you just double that to you know, instead of 10% working, 20% working will completely change the trajectory of innovation”

In the end, she said, few things are more important than health. “It is one of the few things that every single person on the planet ends up caring about”.