Mexico is suspending all non-essential government and economic activities for five days in an effort to contain the H1N1 swine flu virus.
President Felipe Calderon has called on Mexicans to stay home starting Friday, to limit the spread of the flu. Schools, businesses and non-essential government offices will remain closed through Tuesday.
Mexico confirmed 260 cases of the flu Thursday, including 12 deaths. The unofficial toll is higher.
Mexico is the epicenter of the influenza outbreak, which the World Health Organization says has spread to at least 10 other countries.
In the neighboring United States, the Center for Disease Control and Prevention has confirmed 109 cases. A Mexican toddler visiting the U.S. state of Texas died this week, becoming the first fatality outside of Mexico.
The flu has not reached pandemic proportions, but the WHO is asking all countries to combat the spreading virus with "increased urgency."
The U.N. health agency has reported a 75 percent jump in the number of confirmed swine flu cases worldwide since Wednesday. Mexico and the U.S. account for much of the increase.
Some U.S. cities are closing schools, but the government is not closing borders and is encouraging people to travel inside the country as usual.
The head of U.S. Homeland Security, Janet Napolitano, says more than 70 million courses of anti-viral treatments are stockpiled across the U.S., and scientists are working on a vaccine to prevent the flu.
WHO director-general, Margaret Chan says a new pandemic is beginning, with the only uncertainty being how severe the effects of the virus will be.
European Union ministers held emergency talks on the crisis Thursday in Luxembourg. Ministers from the Association of Southeast Asian Nations plan to meet next week to coordinate their response.
Swine flu also has been reported in Austria, Britain, Canada, Germany, Israel, Spain, New Zealand, Netherlands and Switzerland. Australia, Colombia, France, Denmark and South Korea are among nations investigating suspected cases.confirmed 260 cases of the flu Thursday, including 12 deaths