The United States has declared a public health emergency to address the recent outbreak of swine flu.
Homeland Security Secretary Janet Napolitano said Sunday the action will allow authorities to release funding and stockpiles of anti-viral medication.
The acting director of the Centers for Disease Control and Prevention, Dr. Richard Besser, said that so far, 20 cases of swine flu have been confirmed in five U.S. states (Texas, California, New York, Kansas and Ohio). Officials say they expect to see more infections in the coming days.
In neighboring Canada, health officials (in the eastern province of Nova Scotia) confirmed four cases of swine flu among a group of students who recently traveled to Mexico.
Mexican authorities say 86 people have died from the flu, while more than 1,300 others have been sickened. Some churches in Mexico canceled services to prevent transmission of the disease. Officials also called off concerts and sporting matches.
The World Health Organization has declared the virus "a public health emergency of international concern" with "pandemic potential."
Suspected swine flu cases also are being tested in New Zealand, Spain and France.
The WHO is recommending that all countries intensify efforts to track its potential spread, but there are growing concerns about the impact that swine flu may have on air travel.
Authorities in Russia have banned meat imports from Mexico, several U.S. states and some Caribbean countries.
Health officials say the unusual flu strain contains genetic material from pigs, birds and humans. But authorities say none of the U.S. patients had any contact with pigs.
U.S. health officials say swine flu symptoms resemble the regular human seasonal influenza. They include fever, lethargy, lack of appetite and coughing.