"As of 06:00 GMT, 5 May 2009, 21 countries have officially reported 1,124 cases of influenza A (H1N1) infection," the WHO said on its website.
Mexican President Felipe Calderon, whose country has reported 590 laboratory-confirmed human cases, said in a televised address that the spread of the virus is under control.
"We are on the way toward normality," he said.
Despite assurances from the WHO that humans cannot be infected with swine flu via cooked port, Russia's agricultural watchdog banned on Tuesday pork imports from Britain, where 27 H1N1 cases have been reported.
The ban has also been extended to the Canadian province of Alberta.
Russia earlier blocked pork imports from 15 U.S. states as well as from Spain and three Canadian provinces - British Columbia, Nova Scotia and Ontario.
The WHO said in a recent report: "There is no risk of infection from this virus from consumption of well-cooked pork and pork products."