"We made the decision to move people into temporary accommodation.
"I know it's a scary time but we will make sure they are safe.
"We think it is about 800 households but it is an emerging picture".
Gould said safety experts had informed the council at the end of today that they could not guarantee the safety of the buildings.
"We are absolutely clear that we will make sure that everybody on those blocks has somewhere to stay tonight," Gould added.
Residents of the blocks in Swiss Cottage have been advised to go to the local library where they will be allocated a room for the night.
It comes as the Metropolitan Police said it was considering manslaughter charges after disclosing that the cladding and insulation on the outside of Grenfell Tower failed fire safety tests.
It also emerged that the Grenfell blaze was started when a Hotpoint fridge-freezer caught fire. Owners of the same model, of which 64,000 were sold, have been told to contact the company as the Government ordered tests to be carried out on similar models.
Tests on cladding samples from 600 tower blocks in England are being carried out on the orders of the Department for Communities and Local Government, which has now confirmed that those tests extend to hospitals, schools, universities, office blocks and any other public building that has cladding fitted.