The number of suspected cases in Mexico has risen to 1,614
China has banned imports of pork products from Mexico and several US states as part of attempts to prevent a deadly flu virus entering the country.
Japan, Hong Kong, Singapore, Malaysia and Indonesia announced plans to screen travellers for symptoms of swine flu.
Asian governments are on high alert after the World Health Organization (WHO) warned of a possible pandemic.
Asia has battled hard to stem another highly-contagious flu virus, H5N1, which has claimed hundreds of lives.
At least 100 people are now suspected to have died of the disease in Mexico, with the number of suspected infections rising to 1,614.
Outbreaks have also been reported in the US and Canada, and there are suspected cases in Australia, New Zealand, France, Spain, Brazil and Israel.
The WHO, the UN's health agency, has said the swine flu virus could be capable of mutating into a more dangerous strain.
But officials say they need more information on the virus before deciding whether to raise the global pandemic alert phase.
The WHO is advising all countries to be vigilant for seasonally unusual flu or pneumonia-like symptoms among their populations - particularly among young healthy adults, a characteristic of past pandemics.
Beijing has banned pork imports from Mexico and the US states of Texas, Kansas and California with immediate effect, according to state news agency Xinhua.
The Spanish flu pandemic remains the most devastating outbreak of modern times - infecting up to 40% of the world's population and killing more than 50m people, with young adults particularly badly affected
Asian flu killed two million people. Caused by a human form of the virus, H2N2, combining with a mutated strain found in wild ducks. The elderly were particularly vulnerable
An outbreak first detected in Hong Kong, and caused by a strain known as H3N2, killed up to one million people globally, with those over 65 most likely to die
China's Ministry of Health has warned its citizens to be vigilant although it also noted that so far there is no evidence that the new flu virus can be spread through food.
A series of tough measures were also announced in Hong Kong, where the Severe Acute Respiratory Syndrome (Sars) killed hundreds of people in 2003.
All travellers will be screened on arrival and any ill person will be quarantined.
Japan, Singapore, Malaysia and Indonesia have announced similar plans, with many airports using devices that were put in place to monitor Sars and bird flu over the last few years.
H1N1 is the same strain that causes seasonal flu outbreaks in humans but the newly detected version contains genetic material from versions of flu which usually affect pigs and birds.
It is spread mainly through coughs and sneezes.
Officials said most of those killed so far in Mexico were young adults - rather than more vulnerable children and the elderly.
There is currently no vaccine for the new strain of flu but severe cases can be treated with antiviral medication.
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