IMF Managing Director Kristalina Georgieva expects global economic growth projections to be downgraded because of the Omicron variant.
At a conference on Friday, she said the new strains of the virus could rapidly dent confidence.
In October, the IMF already trimmed the global economic outlook from 6 percent to 5.9 percent for this year.
The IMF chief said problems that existed before the emergence of Omicron are now becoming entrenched, including divergences between countries recovering quickly from the pandemic and those that are not.