"Globally we believe that we are at phase five but are getting closer to phase six," said Keiji Fukuda, World Health Organisation assistant director-general, referring to the agency's six-level alert system.
Phase five signals that a pandemic is imminent while the world would be in a full-fledged pandemic -- marking global spread -- at phase six.
"It is clear that the virus continues to spread internationally. We know there are a number of countries that appear to be in transition moving from travel-related cases to established, more established, community-type spread," he added.
A criteria for the WHO to move the alert to phase six would be established community spread in a country outside the first region in which the disease was initially reported, in this case, outside the Americas.
"However, we still are waiting for really widespread community activity in these countries. So I think it's fair to say that they are in transition and are not quite there yet, that's why we are not in phase six yet," Fukuda said.
But he stressed that countries like Britain, Spain, Japan, Chile and Australia were showing larger numbers of A(H1N1) influenza infections, "with some early spread into communities."
Other than geographical spread, member states have asked WHO to integrate an assessment of the disease's severity into its criteria for moving up the alert scale and declaring a pandemic.
Some 18,965 cases of infections including 117 deaths have been reported to the WHO by 64 countries around the world since the virus emerged in the United States and Mexico in April.
The renewed warning came as Canada reported its third swine flu death; two people were hospitalised in Scotland in intensive care, and Egypt and the tiny European duchy of Luxembourg confirmed their first cases of the A(H1N1) virus.
The Egyptian case, the first in Africa, involved a 12-year-old girl with joint US and Egyptian nationality who was quarantined by health workers at Cairo airport on Monday after she showed symptoms of the disease.
Spain, the first European country to confirm a case of swine flu, on Tuesday reported 13 new confirmed cases at three schools in the Madrid region, one of them a kindergarten, bringing to 15 the total number of children affected.
The WHO said on Monday there are 178 confirmed cases of the disease in Spain.
France on Tuesday reported its first locally transmitted case and said the number of confirmed infections had risen to 42.
The health minister of Australia's Victoria state Daniel Andrews said Tuesday 89 new cases had been identified overnight, taking its total to 395.
The national count in Australia now stands at 496, the fourth largest worldwide and the biggest in the Asia-Pacific region.
Australia had only one case of swine flu just a fortnight ago but the numbers have grown exponentially since the controversial move to let infected passengers leave a luxury cruise-liner last week.
On Tuesday, Carnival Australia warned that another of its vessels had been turned away from the French Pacific territory of New Caledonia because of possible flu cases among its passengers