The World Health Organisation is working closely with Mexican officials to make sure drugs are available to fight the outbreak of swine flu, but warns other countries may need more as well if the disease spreads, a senior official said today.

Swiss drug company Roche Holding AG says the World Health Organisation (WHO) has enough of the anti-flu treatment Tamiflu stockpiled to treat up to five million people who come down with the new strain of swine flu that broke out in Mexico.