Japan, Malaysia and Singapore have banned US poultry imports following an outbreak of bird flu in Delaware.
The three countries joined South Korea in banning US poultry imports; Hong Kong banned the import of live birds and poultry from Delaware only.
Delaware officials ordered the destruction of some 12,000 farm chickens on Friday after confirming a flock there was infected by bird flu. The birds have a strain of the disease milder than the one devastating Asia's poultry stocks.
Today, Vietnamese health officials confirmed two more cases of bird flu in people, including one man who died, bringing the country's death toll to 14 and Asia's overall toll to 19.
More than 50 million chickens have been slaughtered in Asia to stem the spread of the virus.
The Asian governments fighting the outbreak include Thailand, China, Vietnam, Laos, Cambodia, Indonesia, Japan, South Korea, Pakistan and Taiwan. The strain afflicting Pakistan and Taiwan is milder, however, and not considered dangerous to humans.
Bird flu has not jumped to people anywhere outside Vietnam and Thailand in the current outbreak. Health officials have traced most of those cases directly to contact with sick birds. So far, there have been no known cases of person-to-person transmission in the current Asian outbreak.