World ready to withstand potential pandemic: WHO

* World better prepared than 5 years ago for pandemic

* WHO has begun work to prepare swine flu vaccine if needed

* "Zero evidence" of infection from pigmeat or pigs

GENEVA (Reuters) - The world is better prepared than ever to withstand a potential flu pandemic after five years of gearing up for bird flu, the World Health Organization (WHO) said on Sunday.

Keiji Fukuda, acting director-general for health security and environment, also said the WHO had begun preliminary work with laboratories to prepare a vaccine against swine flu if needed.

"I believe that the world is much, much better prepared than we have ever been for dealing with this kind of situation," Fukuda told a teleconference on the outbreaks of swine flu in Mexico and the United States.

"The past five years have put us in (the) best possible position to handle this kind of situation," he said.

The WHO had a stockpile available of 5 million treatment courses of the antiviral Tamiflu, by Swiss drugmaker Roche Holding AG which has proven effective against the virus, he said. Countries and regions also have stockpiles.

"If this situation escalates then I think that the demand for antivirals clearly will also escalate and then this will require both the stockpiles and probably increased production of this drug," Fukuda said.

There was "zero evidence" that people are getting infected with the new virus from exposure to pigmeat or pigs, he said in response to reports that some countries were banning imports of meat from Mexico.

(Reporting by Jonathan Lynn and Stephanie Nebehay; Editing by Angus MacSwan)