Sussex firm Rydon, which carried out a £8.6 million refurbishment of the exterior of Grenfell Tower last year, installing cladding and new windows, said its work "met all required building control, fire regulation, and health and safety standards".
Portsmouth City Council is removing cladding from two high-rise buildings as a precautionary measure.
Following independent testing, cladding on Horatia House and Leamington House in Somerstown is being removed to ensure the highest safety standards are in place. No other blocks are affected.
Cllr Luke Stubbs, Deputy Leader of Portsmouth City Council, said: "The safety of our residents is an absolute priority.
"Like all councils, we have been working with the government and fire service to review our buildings. As a precaution we submitted some cladding for testing and the results that came back said the cladding on Horatia House and Leamington House was a fire risk.
"As a result we are removing the cladding from those buildings. Protection of Portsmouth's residents is our number one priority and we will not comprise on safety standards.
"We will be removing the cladding as quickly as we can. In the meantime we would like to reassure residents we have conducted a full assessment of the buildings, with Hampshire Fire & Rescue Service, and the buildings are safe to stay in with all of the existing safety measures still in place."
The fire service in Dorset & Wiltshire is to inspect fire safety at up to 250 high rise apartment blocks after the Grenfell Tower tragedy.
Several residents reported that a resident said the blaze started in his faulty fridge.
Local residents had warned it would take a "catastrophic event" before authorities took notice of their concerns about fire safety.