Mexico City authorities on Friday announced restrictions on alcohol sales to discourage parties and warned the city was close to another lockdown after nationwide coronavirus deaths soared past 100,000.

Mayor Claudia Sheinbaum said that the capital was "at the limit" of its current status of orange under a traffic-light system introduced in response to the pandemic.

A return to red would see non-essential activities suspended again in the city of nine million people.

Sheinbaum appealed for "urgent" cooperation from the capital's residents to reduce hospitalizations.

She said alcohol sales would be banned in half of the city's 16 municipalities this weekend, and in the other half the following weekend.

Mexico's official coronavirus death toll reached 100,104 on Thursday -- the fourth highest in the world -- although limited testing means the actual figure is believed to be much higher.

The government imposed lockdown measures at the end of March and started gradually reopening the economy in June.