In a pre-recorded televised address broadcast Saturday as demonstrators again started to march, many wearing face masks in defiance of a new ban, a solemn Carrie Lam did not announce additional measures to quell increasingly violent protests.
She defended the legality of the ban criminalizing the wearing of masks at rallies that took effect at midnight.
Describing Hong Kong as being in the grips of "unprecedented violence," Lam said that "to protect citizens' daily lives and freedoms, I cannot allow the small minority of rioters to destroy that."
All subway and trains services are closed in Hong Kong after another night of rampaging violence that a new ban on face masks failed to quell.
After widespread overnight arson attacks, looting, fighting with police and beatings, the government on Saturday called on the public to swing behind it in condemning the increasingly violent protests.
John Lee, the government's security secretary, says by not condemning violence, people are stoking it.
The MTR transport network, a frequent target of rioters, says all its services are suspended, including the rail line to Hong Kong international airport.