But Lopez Obrador predicted that "this virus is on its way out" and that "things will get back to normal very soon".

The president appeared on a video feed at the morning press briefing he normally runs at the National Palace in Mexico City.

He suggested he had the Omicron variant, saying "fortunately, this variant does not have the degree of danger that Delta did, and I am experiencing that".

Lopez Obrador said he had no fever and his oxygenation was good.

"It is like a cold," he said of his symptoms.

The president is fully vaccinated and has had a booster shot.

Health Secretary Jorge Alcocer said Lopez Obrador could return to the briefings as early as next week.

In 2021, Lopez Obrador returned to his daily news briefings in February after a two-week absence when he caught coronavirus in January.

At the time, Lopez Obrador revealed he received experimental treatments, which he described only as an "antiviral" medication and an anti-inflammatory drug.

This time around, the president said he was taking only paracetamol, a mild pain medication.

On Monday, the president told Mexicans to just assume they had COVID-19 if they had symptoms.

The number of confirmed cases spiked by 186 per cent last week.

Lopez Obrador called the Omicron variant "a little COVID," noting hospitalisations and deaths had not increased at the same rate as new cases.

However, experts say those are both lagging indicators that may not show up for weeks after infections spike.

In the US, where the Omicron wave hit before it did in Mexico, COVID-19 deaths have again started to rise.

Reading advice posted on Twitter, the president said Mexicans with symptoms should just stay at home, take paracetamol and isolate rather than going out and trying to find tests.

Since Christmas, private pharmacies and the few available testing centres have been overwhelmed by long lines.

The Twitter advice drew on guidelines from Mexico City and other health authorities.

Lopez Obrador's administration has long refused to implement mass testing, calling it a waste of money.

He called on companies not to require COVID-19 tests for employees.

Mexico has also been one of the few countries not to impose lockdowns, flight bans or mandatory face mask requirements.

Mexico passed 300,000 test-confirmed coronavirus deaths last week but so little testing is done in the country of 126 million that a government review of death certificates puts the real toll at almost 460,000.

Australian Associated Press