Mexico's government said on Saturday the country's H1N1 flu outbreak appeared to be stabilizing, though its confirmed death toll crept up to 19, and more cases cropped up across the globe.
Health Minister Jose Angel Cordova said testing had detected three more deaths since Friday. The total number of patients infected rose to 454 from 427.
The last death recorded by labs going through a backlog of suspect fatalities was on April 28, he added. Fourteen of all the deaths were women.
Cordova, who earlier said the epidemic appeared to be "in a stabilization phase," suggested the flu was less lethal than initially feared.
"Each day we're seeing fewer serious cases and therefore the mortality rate is dropping," Cordova said.
Mexico is at the epicenter of the flu epidemic, recording most of the infections worldwide and all the deaths except for one -- a Mexican child on a visit over the border in the southern United States.
Mexico's cases were concentrated in the highly-populated area of the Valley of Mexico, which includes Mexico City.
In Geneva, a World Health Organization official said the virus had not spread in a sustained way outside of the Americas, a condition necessary to declare a full global pandemic.
WHO, which has reported at least 615 cases in around 15 countries, was maintaining its second-highest level of alert which predicts an "imminent" pandemic.
A senior WHO emergency response official said the body was still trying to determine the severity of the new swine flu virus in Mexico.
A handful of countries have suspended flights to Mexico, as well as cruise ship visits to Mexican ports and tour company cancelations, dealing a heavy blow to the country's economy, already hard hit by the economic crisis.
Mexico's foreign minister on Saturday berated countries which have cut Mexico flights, including China as well as Argentina, Peru, Ecuador and Cuba.
"We're surprised by the adoption of unjustified measures," Espinosa said.
Espinosa also advised Mexican citizens to avoid travel to China after a Mexican family got caught up in strict health measures imposed there after a sick Mexican tourist who arrived in Hong Kong from mainland China tested positive for H1N1.
President Felipe Calderon discussed the crisis with US President Barack Obama on Saturday, the White House said, underlining the importance of close US-Mexican cooperation.
In the United States, a health official on Saturday did not rule out the possibility that the H1N1 virus outbreak may have originated in California, based on cases reportedly detected in March, before Mexico's flu crisis.
Mexico joined the United States and Canada on Saturday in hitting out at countries which had slapped bans on their pork products despite the fact swine flu cannot be contracted from pig-meat consumption.
In Mexico, lingering fear over the epidemic saw millions observing a call by Calderon to "stay at home" for a five-day long weekend in a bid to contain the virus.
All but essential business and offices were closed for that period, along with schools, popular tourist sites, and all bars, restaurants and cinemas in the capital.
The city's mayor, Marcelo Ebrard announced sanitary controls to prepare for the end of the virtual shutdown due next week, but warned that life would not be the same.
"We are not going to return to a normal situation without the virus, we're going to live in a new situation: living with the virus. This is the next step," Ebrard told a news conference.
The flu did not stop Mexican's drug violence -- in which more than 7,300 have died since the start of last year -- with 17 killed in separate attacks Saturday, including a human head found in a dairy dustbin in central Mexico.