President Barack Obama said today that the threat of swine flu spreading is a cause for concern but “not a cause for alarm” as the United States works to closely monitor borders to contain it.

“The Department of Health and Human Services has declared a public health emergency as a precautionary tool to ensure that we have the resources we need at our disposal to respond quickly and effectively,” Obama said in an Associated Press report from a gathering of scientists in Washington, DC.

The acting head of the Centers for Disease Control and Prevention (CDC) said people should be prepared for the situation to possibly become more severe, according to Richard Besser.

To date, the number of swine flu infections in Mexico has risen to 1,600, and a number of nations have provided varying responses:

--The European Union advised against nonessential travel to the United States and Mexico.

--Tokyo’s Narita Airport installed a device to monitor the temperatures of passengers arriving from Mexico.

--Russia said any visitors from North America running a fever would be quarantined until the cause of that fever is determined.

The U.S. Department of Agriculture (USDA) reassured the public Sunday that there is no evidence at this time to suggest that swine have been infected with this virus.

“According to scientists at USDA and the CDC, swine flu viruses are not transmitted by food so you cannot get swine flu from eating pork or pork products,” says Secretary of Agriculture Tom Vilsack. “Eating properly handled and cooked pork or pork products is safe. Cooking pork to an internal temperature of 160 degrees F kills all viruses and other foodborne pathogens.” More details on cooking pork are available at The National Pork Board.

USDA currently has a surveillance system in place in all states to monitor animal health. Vilsack says he has asked USDA officials to contact agricultural officials in every state to affirm that they have no signs of this virus type in their state.