President Xi Jinping said China must stick "unswervingly" to its zero-Covid strategy, as more than half of Shanghai's 25 million lockdown-weary residents got ready for a weekend virus testing drive.
China is the last major economy still pursuing a policy of stamping out all outbreaks, wielding snap lockdowns, mass testing and mandatory quarantines.
But the strategy has come under heightened scrutiny after the fast-spreading Omicron variant triggered sweeping restrictions in major cities such as Shanghai and Beijing, hammering the world's second-biggest economy.
Chinese leaders have attempted to thread the needle between crushing the virus and limiting the damage of lockdowns, with Mr Xi calling for "efficiently coordinating Covid-19 prevention and control with economic and social development".