Hertfordshire Police has said that is 'not expecting' to see any military presence on the county's streets following the Manchester bombing.
The nation's UK Terror Threat level was raised to critical this week, following the suicide bombing at the Ariana Grande concert on Monday which killed 22 people.
The increase of the threat level to critical indicates that an attack may be 'imminent', and that military forces may be deployed to certain areas.
But Hertfordshire Police has reassured residents that seeing such forces deployed to the county would be unlikely, but it urged residents to remain "vigilant".
A spokesman for the Constabulary said: "We are reviewing our operational response plans following the raising of the UK Terror Threat level to critical, which means that a further attack in the UK could be imminent.
"There are considerable operational implications to such a move for the police service as you would expect, and a dedicated strategic response group has already been established to assess what the announcement means for Hertfordshire.
"The Constabulary is in contact with the Home Office and other forces across the country, sharing information and getting the latest assessments to ensure plans are proportionate.
"In terms of army deployments into the county, it’s not expected at this stage that we will see any military presence on the streets in Hertfordshire but there will be a heightened police presence if required.
"The force’s priority and focus remains public safety and members of the public are urged to remain vigilant and report anything suspicious to police via 999."