U.S. President Barack Obama says the threat of a swine flu epidemic is cause for concern, but not alarm. There have been 149 suspected swine flu deaths in Mexico but none in the United States.
President Obama says the United States is closely monitoring the spread of the new flu strain.
"This is obviously a cause for concern and requires a heightened state of alert," said President Obama. "But it is not a cause for alarm."
On Sunday, the U.S. government declared a public health emergency as a precautionary measure. The move allows the government to move resources into place, similar to steps taken in preparation for a hurricane.
So far, the impact of the swine flu outbreak in the United States has been slight with only a few mild cases reported in five states.
But across the border in Mexico - where the death toll is rising - it is another story.
Dr. Richard Besser is the acting head of the Centers for Disease Control and Prevention - the U.S. agency that tracks infectious diseases. He warns that Americans should not be complacent.
"I wouldn't rest on the fact that we have only seen cases in this country that are less severe," said Dr. Besser. "As we continue to look, I expect that we will see additional cases and I expect that the spectrum of disease will expand."
Besser says the United States will be advising its citizens to avoid non-essential travel to Mexico.
At the State Department, which issues formal travel advisories, Secretary Hillary Clinton said cross-border cooperation will be essential in battling the spread of swine flu.
"And we obviously have offered help and assistance to the government of Mexico to make sure that they have the resources and the technical expertise that they might need, if they so request," said Secretary Clinton.
The U.S. official overseeing the domestic response to the swine flu threat is Janet Napolitano, the Secretary of Homeland Security. She says the United States is stepping up checks of people entering the country, stopping those showing signs of infection.
But she says the biggest weapon in fighting the disease might be common sense.
"Common sense means washing hands, staying home from work or school if you feel sick, covering your mouth if you cough or sneeze," said Janet Napolitano. "These are straightforward and simple measures, but they can materially improve our chances of avoiding a full fledged pandemic."
Napolitano vows to keep the public informed. The White House says she will provide daily updates as long as the swine flu threat persists.