U.S. president Barack Obama said on Saturday he will take whatever necessary measures to prevent the flu outbreak and protect the safety and security of the American people.

Unlike the various strains of animal flu that have emerged in the past, it's a flu that is spreading from human to human. This creates the potential for a pandemic, which is why we are acting quickly and aggressively, Obama said in his weekly radio address.

The new virus has been identified in 15 countries and 615 cases had been infected including 16 deaths in Mexico and one death in the United States, according to the WHO's website.

We have asked every American to take the same steps you would take to prevent any other flu: keep your hand washed; cover your mouth when you cough; stay home from work if you're sick; and keep your children home from school if they're sick.Obama said.

He said the good news is that the current strain of H1N1 can be defeated by a course of antiviral treatment and the United States had began this week with 50 million courses of this treatment in the Strategic National Stockpile.

Out of an abundance of caution, I have also asked congress for $1.5 billion if it is needed to purchase additional antivirals, emergency equipments, and the development of a vaccine that can prevent this virus we prepared for the next flu season in the fall, Obama said.

He also paid tribute to works the Bush administration did in 2005 to prepare for a possible avian flu pandemic, saying it put the government in a better state of readiness to meet the current outbreak.

It is my greatest hope and prayer that all of these precautions and preparations prove unnecessary, I have on higher priority than the safety and security of the American people, and I will do whatever is necessary to protect this country. he said in the end of his speech.