The measures include a ban on public gatherings of more than four people and the closure of six types of venues are due to expire on Thursday midnight, China's state-run media agency, CGTN reported.
Lam made the remarks at a press conference, stressing that the anti-epidemic measures cannot stop at present, or all the efforts that Hong Kong has made thus far could be wasted.
Hong Kong's Center for Health Protection said no new confirmed cases of the COVID-19 were recorded in Hong Kong on Monday, the first time in more than 45 days, and the total case tally remained at 1,025.
After weeks of a surging number of imported cases as well as local clustered outbreaks, Hong Kong has recorded daily increases in the single digit for more than a week.
Lam also appealed to the public to be patient for a little longer in the battle against the virus.
( With inputs from ANI )