The policing minister should help with the "extraordinary level of demand" facing officers following major incidents in Amesbury and Salisbury, Wiltshire's police commissioner said.
Angus Macpherson said he had spoken to policing minister Nick Hurd to ensure the "increased pressure" was addressed.
The comments were made shortly before police cordoned off a road in Salisbury after a man was reported to be ill.
Officers later said there was "no concern" for the man's health.
On Friday, police said the 33-year-old was cautioned after being arrested on suspicion of being drunk and disorderly.
A test for the nerve agent Novichok was carried out on the man at Salisbury District Hospital, but proved negative.
Police added there was also no "wider risk to the public".
Mr Macpherson said the resources of forces across the country were also being stretched by the US presidential visit, the Royal International Air Tattoo and large summer events.
He said Mr Hurd had reassured him "the current approach to policing cordons, in relation to the ongoing major incidents in Amesbury and Salisbury, is under review to help me ensure that policing services more widely across Wiltshire and Swindon remain unaffected".
Mr Macpherson added: "Wiltshire Police has received great support from almost every police force across the county since the first major incident was declared in March.
"Alongside the chief constable I couldn't be more grateful for the help and support of those forces, however, with more and more rest days being cancelled and annual leave requests being put on hold, we must now explore a different approach."
Police cordoned off Castle Street in Salisbury at about 18:20 BST on Thursday after a man in his 30s was reported to be ill, near the Zizzi restaurant where ex-Russian spy Sergei Skripal and his daughter Yulia dined before they fell ill.
It was reopened just after 21:00 BST.
On Twitter, Salisbury Police said the man had been taken to Salisbury District Hospital and was "fully assessed by medical staff".
"We understand that our initial response to the incident may have looked alarming, but we hope you appreciate why we needed to take this highly precautionary measure," they added.
We are pleased to report that the cordon in place in Castle Street, Salisbury, has been removed and the road has been reopened. Emergency services were called to the scene at 6.20pm this evening (12 July 2018) after concerns were raised about the welfare of a man in his 30s. pic.twitter.com/3ylvkAB8ui— Salisbury Police (@SouthWiltsCPT) July 12, 2018
Earlier a witness, who asked not to be named, said the man involved was a "local homeless guy" who was "sat on the floor, completely conscious, talking".
He said he saw a paramedic putting on a chemical suit while another "was shouting at the man to stay put and stay on the floor".
The Skripals were discovered unconscious on a bench in March after being poisoned with the nerve agent Novichok.