About 12,000 pigs have already been slaughtered in the UK in an attempt to stop the spread of the disease.
The temporary restriction comes following the discovery of the highly contagious swine fever among pigs on several farms in East Anglia.
The European Commission has already imposed a ban on live English pig exports and pig sperm, used for breeding, until the end of August at least. Pork exports are as yet unaffected.
Lisa Ferguson, a spokeswoman for the US Agriculture Department said there were concerns about the transmission of the disease to America's livestock population, adding that the hold on shipments was "temporary".
Canada acts
Several shipments are known to already be in transit and American officials are said to be seeking more information about their origins from the UK Ministry of Agriculture.
Ms Ferguson said each import would now be dealt with on an individual basis and that would remain the case until the risk of disease was over.
Andrew Garvey of the Meat and Livestock Commission (MLC) said he respected countries' wishes to impose a temporary ban, but hoped the export of livestock would resume as quickly as possible.
"This disease is very virulent, and we understand any country that has a view about minimising the risk of bringing that disease into their own country," he said.
"But we do want to resolve this issue very quickly, and our hope is that we can negotiate for exports to continue from areas of the country that are not infected."
He said the industry and the Ministry of Agriculture were working "very closely together" to minimise the spread of disease and restore confidence.
Over 100 ministry staff are now investigating the source of the outbreak in East Anglia, he pointed out.
EU experts meet
Officials from the Ministry of Agriculture, Fisheries and Food (Maff) are due to meet their EU counterparts in Brussels on Wednesday to review the swine fever situation.
A Maff spokesman said: "Our officials are going to Brussels to hold informal meetings to discuss the scale of the problem and talk about steps forward both in terms of protecting the pigs in the EU and UK."
About 12,000 pigs have already been slaughtered in the UK in an attempt to stop the spread of the disease.
According to Maff there were no new confirmed cases of the disease on Tuesday but further test results, from farms including were still being awaited.
Government restrictions on the movement of pigs and other livestock have been imposed on farmers in affected areas.
The European Commission's Veterinary Standing Committee is due to meet to discuss the EU ban on 22 August.
'Devastating effect'
But the MLC has warned a prolonged ban could have a "devastating effect" on the industry, which is worth £12m in exports and accounts for 15% of the market.
Mr Garvey said the industry had already been in crisis for two years, but had moved into a recovery position.
Shadow agriculture minister Tim Yeo warned the ban could get out of control and extend to pork itself.
He said: "It's time Nick Brown stopped sitting around waiting for the French to tell British pig farmers which hoop to jump through next.
"He must act today to stop the ban on the movement of live pigs for export becoming a ban on the export of fresh British pork."
The Liberal Democrats have urged Maff to consider compensation for the affected farmers.