The nomination period was due to begin on Sunday for the election originally slated for March 27.
The nomination period will now take place between April 3 and 16.
"For public health, our government needs to focus on the epidemic. [Our attention] cannot be diverted and we cannot afford to lose," Lam told a press conference.
"This matches the spirit of President Xi Jinping's important directive – that controlling the epidemic is the overriding mission, over anything else."
Lam said the Chief Executive in Council has agreed to invoke emergency laws to postpone the election.
Two years ago, the Hong Kong government also cited the novel coronavirus pandemic in its decision to postpone for a year the Legislative Council elections originally scheduled to take place in September 2020.
Lam said the COVID019 situation now was far worse than that in 2020, with thousands of infections being reported each day.
In a statement, the Hong Kong and Macau Affairs Office (HKMAO) in Beijing said it supports the Hong Kong government's decision, as officials in the special administrative region (SAR) needed to concentrate on anti-epidemic efforts and safeguard social stability.
The Central People's Government Liaison Office in Hong Kong, meanwhile, said the postponement was in line with Hong Kong's overall interest.
- RTHK, MPD
Caption: Hong Kong CE Carrie Lam Cheng Yuet-ngor addresses a press conference in Hong Kong yesterday about the postponement of the chief executive election scheduled for March 27 to May 8 due to the current COVID-19 outbreak in the city. - Xinhua
