President Barack Obama met with some of his top officials to discuss vaccine development and measures Americans should take to deal with the swine flu virus, said John Brennan, White House deputy national security adviser.

Obama is expected to travel to Guadalajara, Mexico, on August 8 for talks with Mexican President Felipe Calderon and Canadian Prime Minister Stephen Harper.

Brennan said the three leaders will issue a joint statement about the collaboration they are taking to address H1N1 in coming weeks and months to try to limit its severity.

The first vaccines to combat H1N1 should be approved and ready for use in some countries beginning in September, said the World Health Organization said.

In its latest update, the World Health Organization reported 162,230 confirmed cases and 1,154 deaths from the virus. But flu experts said this probably reflected only a fraction of the true count as not every patient can be diagnosed with a lab test.