Commander Stuart Cundy said that number "may increase".
The recovery operation at the burnt-out block of flats has resumed and could take weeks, he said.
Meanwhile, PM Theresa May admitted support for families in the "initial hours" was "not good enough".
The statement came after
As they left Number 10, one representative spoke to reporters briefly, saying they would not make a full statement yet.
"We will be making this in the community, with the community," he said.
"We have had two-and-a-half hours with the prime minister in the last 48 hours and spoke about demands and what we expect."
Council leader Nicholas Paget-Brown said "lessons must be learned", adding that he was "heartbroken by the tragic fire and the appalling loss of life.