Airlines and tour operators suspended flights to Mexico on Tuesday as new cases of a deadly strain of swine flu were confirmed across the globe and officials warned of more fatalities.
The United States cautioned it may soon see its first deaths from the virus, which thus far has proved fatal only in Mexico, where more than 150 people are believed to have died from the flu.
US health authorities on Tuesday raised sharply the number of confirmed US cases to at least 65, and California declared a state of emergency.
Costa Rica became the first Central American nation to detect a confirmed case, while Europe, Israel and New Zealand increased their counts.
The World Health Organization (WHO) said it would convene experts from affected countries on Wednesday, and they would give a briefing on what is known about the disease.
The body has increased its official level of alarm but not declared an outright pandemic, despite the spread of the flu from Mexico to seven other countries.
But it was clear many companies and authorities were already treating the emergency as a global issue.
"Swine flu is an international problem now, it's crossed two continents, it's got to be dealt with by international agreements," British Prime Minister Gordon Brown told reporters in Poland.
The United States named nine countries that have erected trade barriers to US pork and swine imports amid the swine flu epidemic despite experts' insistence that the virus -- a version of swine flu identified as A/H1N1 -- could not be caught from eating meat from pigs.
Seven countries had imposed bans on pork and pork products from the United States: China, Ukraine, Kazakhstan, Philippines, Thailand, United Arab Emirates and Ecuador, Nefeterius McPherson, a spokeswoman for US Trade Representative Ron Kirk, told AFP.
China, which has the world's largest pig population, and South Korea have banned live swine from the US, McPherson said, and Russia has banned all meat products from five states: California, Texas, Kansas, New York and Ohio.
US and WHO officials were reportedly debating whether to change the common name for the virus from "swine flu" to another nomenclature, possibly "North American flu" to dissociate it from perceptions it was spread through contact with animals and animal products.
The governments of Australia, Britain, Canada, France, Sri Lanka and Switzerland became the latest to advise against travel to Mexico, while Cuba suspended all flights to and from Mexico until Friday.
A Canadian airline, Air Transat, said it was halting flights to Mexico until June 1, and French and British travel firms announced they, too, were suspending trips to the country. Germany's leading tourism group TUI said Monday it would cancel Mexico City visits until May 5.
US President Barack Obama is seeking 1.5 billion dollars from Congress to boost US efforts to contain the flu's spread, the White House said.
The urgency given to his move came as authorities in California declared their state of emergency and said they had detected a death in Los Angeles that might have resulted from the virus. Another suspect death was found to not be flu-related.
World oil prices dropped further Tuesday to just under 50 dollars a barrel, extending a decline seen Monday on fears the flu would sap a nascent recovery from the global financial crisis. US stocks also dipped on the fears.
In Mexico, the capital ordered the closure of all venues where people congregate, including eateries, bars, gyms and cinemas, in a further clampdown against the disease.
The country's federal government had already closed schools and restricted the opening of bars and restaurants as it grapples with a toll of 20 confirmed flu deaths and the deaths of another 132 likely due to the virus.
Mexico has more than 1,600 cases of patients suspected to be infected with swine flu, overwhelming its health system.
|A man works inside a pigsty in a farm in Mexicaltzingo, Mexico.|
Amid the strenuous reactions to the flu, questions were being asked about particularities of this flu virus, namely: Why have all the confirmed deaths so far been in Mexico? And how easily can the virus spread?
"We don't have information on how it acts, how it transmits," said Gregory Hartl of the World Health Organization.
Theories included the patients who died in Mexico being treated too late or with insufficient antiviral drugs, or that, possibly, the H1N1 viral strain had mutated into a less virulent form as it moved out of Mexico, according to John Oxford, a top virologist at the Royal London Hospital.