World Health Organization (WHO) Director-General Dr. Margaret Chan and health ministers from around the world met Thursday in Cancun, Mexico for a two-day summit to design strategies for combating the swine-flu pandemic. “As we see today, with well over 100 countries reporting cases, once a fully fit pandemic virus emerges, its further international spread is unstoppable,” Chan said during opening remarks. Mexican officials wanted the meeting held in the Caribbean resort city of Cancun—where tourism has plunged—to highlight the country's success in controlling its epidemic with a five-day national shutdown of schools and businesses in May. The measures were welcomed by international health officials. “Our presence here is an expression of confidence,” Chan said. “Mexico is safe. However, swine flu is rampant in the Southern Hemisphere and is spreading rapidly through Europe, with Britain projected to reach 100,000 daily cases by the end of August, and the virus is showing signs of rebounding in Mexico. Mexico is starting to see an increase in swine-flu cases in isolated areas, including in southern Chiapas state and the state of Yucatan, adjacent to where Cancun is located. Officials are concerned that the country may see a resurgence, especially when its winter flu season starts in November. With the Southern Hemisphere in the middle of its winter flu season, the WHO's Chan said officials are closely watching those countries. U.S. Health Secretary Kathleen Sibelius said the United States will give 420,000 Tamiflu treatments to the Pan American Health Organization to be distributed in Latin America and the Caribbean. Chile's epidemic has closely followed outbreaks in Mexico and the United States, and its cases have grown to above 7,000, with 15 deaths. Argentina has more than 1,500 cases and ranks first in South America with 26 deaths. Under public pressure, the country's government this week announced schools would close Monday for an extended winter break. Australia has the most cases in the Asia-Pacific region, with more than 4,500 confirmed. Ten people have died.