US health officials are considering buying thousands of doses of flu vaccine from Britain because it is running short of supplies.
The US needs extra vaccine supplies
Parts of the US have been affected by the Fujian flu strain, which has also hit the UK.
At least 20 children have already died from the flu in Colorado, New Mexico, Oklahoma and Texas.
In a normal year 36,000 people catch flu and die, and experts believe those numbers could double this year.
However, the BBC's Justin Webb in Washington says experts believe it is still too early to declare that an epidemic is under way.
The UK Department of Health said the US would talk directly to suppliers and any deal would not affect NHS patients.
The main manufacturers of flu vaccine in the US say they have already distributed all their supplies - around 80 million doses - to doctors, hospitals and clinics.
But states are reporting they are already running low, and stocks could run out within days.
Last year, flu-vaccine manufacturers in America overproduced and had to scrap 12 million doses of the vaccine.
But this year, a combination of more cases of flu and an increase in the numbers choosing to have the flu jab has led to the shortage, experts said.
The US Centres for Disease Control and Prevention said it was considering approaching the Chiron Corporation, which manufactures flu vaccine in Britain, in a bid to access extra supplies.
Its director Dr Julie Gerberding, said the British vaccine uses the same formula as those produced in America.
She said Chiron had about a half million doses of flu vaccine in the UK that might be available.
Dr Gerberding said: "We're aware that they have vaccine, and we're exploring whether or not we would be able to clear that vaccine for use in the United States in time to have any impact on this year's outbreak."
She said the CDC was working with the US Food and Drugs Administration to explore ways of accessing supplies of vaccine from outside the US.
Eduardo Sanchez, Commissioner of Health for the State of Texas, told the BBC: "It's not usual to look abroad for supplies.
"In the US, we tried to encourage more of our population to get their influenza vaccine, and we have been successful in doing that.
"But at the same time, by coincidence, we're having a flu season that's particularly early and particularly severe."
A spokeswoman for the Department of Health told BBC News Online that any deal the US came to with Chiron would not affect the stocks already set aside for NHS patients.
Rob Budge, a spokesman for Chiron UK, which has already supplied around 38m doses to the US, told BBC News Online: "This is not taking away from UK supplies. It is extra material we have already produced."
And he said even if the deal with the US went ahead, it would not mean the UK could not access extra supplies if it too ran short.
"The US is quite a different marketplace. There are only two major suppliers for a very large market.
"In the UK, there are twice as many suppliers for a smaller market, so if more vaccine was needed, there would be more people to go to."