The head of the NHS in England has said he is “really worried” about medicine supply issues.

A number of experts have raised concerns about cost implications and supply disruption linked to the war in Iran.

The NHS England chief executive, Jim Mackey, was asked during a phone-in on LBC Radio what contingency planning was in place because “the UK imports 75% of its medicine”. He said: “We are really worried about this. We’ve already had a couple of supply shocks in the last 12 to 18 months of key supplies.”

He said a team was in place to “focus on where the risks might be through the supply chains”.

Asked how much supply there was, he replied: “It depends what you’re talking about. In every area, we’ve got enough to get through for a reasonable period … so generally, a few weeks.

“Because things perish and it costs money to store and various other things go out of use, you can’t hold years and years of supply, generally dependent on the product we keep a reasonable period. Some of that is held centrally, some held locally.”

Questioned whether, in some instances, it would be “weeks’ worth of supply”, Mackey said: “Yeah, it could be days for some products.”

Henry Gregg, chief executive of the National Pharmacy Association, said: “We’re not currently seeing shortages of medicine directly linked to the conflict in the Middle East, but pharmacies are seeing disturbing spikes in prices, which can be an early indicator of challenges.

“The Department of Health have issued unprecedented numbers of price concessions designed to cope with price surges, which are likely exacerbated by this current situation.”

A government spokesperson said: “There are currently no reported medicine shortages as a result of conflict in the Middle East. We continue to monitor the situation closely for any impacts on the medical supply chain.

“The department actively monitors emerging threats to supply resilience and has established processes in place to manage disruption across the health and social care sector.”