The fire began in a vape shop on Union Street on Sunday afternoon before the building collapsed hours later.
Lamin Kongira told BBC Scotland News he had been walking past when a shopkeeper ran out saying "fire, fire".
The chancellor said a meeting on Wednesday will explore ways to help households.
The prime minister was speaking as oil prices soar in response to turbulence in the Middle East.
A protest by anti-monarchists is staged outside the Commonwealth Day service at Westminster Abbey.