US President Barack Obama said on Friday that he was still optimistic on the effective response to the outbreak of the A/H1N1 flu that has spread nationwide in the country.

Obama told reporters after his meeting with cabinet members that his current priority has been "the health and safety of the American people" since the flu hit the US.

"I'm optimistic that we are going to be able to manage this effectively, but we still have more work to do," he said. "Overall, I am very pleased with the progress that we've made."

The president called on all government agencies to coordinate their work to battle the A/H1N1 outbreak, giving to the fact "this will end up being more severe" than other strains of seasonal influenza happened before.

"We are essentially ensuring that in the worst case scenario we can manage this appropriately."

A total of 141 human A/H1N1 cases have been confirmed in the United States, according to the US Centers for Disease Control and Prevention reported on Friday.

(Xinhua News Agency May 2, 2009)