The global tally of confirmed swine flu cases in 40 countries rose by 1,001 in a day to 9,830, with 79 deaths, the World Health Organisation said on Tuesday.
Some 545 of the new confirmed cases and four of the additional deaths recorded since Monday were reported by Mexico, while 409 new cases and one additional death were reported by the United States, data posted on the WHO's website showed.
The third most infected country was Japan, which has been the focus of most recent concern because of the sudden spike in infections there that has prompted authorities to close thousands of schools.
Japan reported 34 new cases bringing the national total to 159, according to the WHO's daily update.
The other new cases were recorded in Chile (three, for a total of four), China (one, total seven), El Salvador (two, total six), Panama (five, total 59), Peru (one, total two) and Britain (one, total 102).
The WHO data refers to laboratory confirmed cases reported by countries at 0600 GMT on Tuesday, and includes cases from previous days or weeks that have only just been confirmed by testing.
On Monday, the tally stood at 8,829 cases in 40 countries with 74 deaths.