The flu strain may be responsible for more than 40 other flu-related deaths and more than 1,000 people are believed to be infected, according to Mexico health officials.
The virus was originally thought to be a strain of swine flu but closer analysis showed it is a never-before-seen mixture of swine, human and avian viruses, according to the CDC, reported Reuters.
"We certainly have 60 deaths that we can't be sure are from the same virus, but it is probable," said Health Secretary Jose Cordova.
The Mexico City government has also suspended all large public events until further notice, the capital's health secretary said Friday.
President Felipe Calderon cancelled a trip to meet about the response to the disease. The government has 500,000 flu vaccines, which it plans to give to health workers who are most at risk. There are no vaccines available for the general public.
Humans can occasionally catch swine flu, a respiratory disease which infects pigs -- but it is rare that the flu could then be passed on to other humans. Mexico's government warned people not to shake hands or kiss when greeting or share food, glasses or cutlery.
The World Health Organization convened an emergency committee meeting on the outbreak Friday.
"We are very, very concerned," said Thomas Abraham, a spokesman for the WHO. "We have what appears to be a novel virus and it has spread from human to human."
The WHO said it had prepared "rapid containment measures" in case they were needed, but Mexico's government announced it has no plans to close its borders and the WHO has said travel restrictions are not needed at this point.
If international spread of the virus is confirmed, the outbreak would meet the organization's criteria for raising the pandemic alert level.
Samples of the virus were sent to the U.S. Centers for Disease Control and Prevention in Atlanta, Georgia, to determine whether it's the same virus that infected eight people in Texas and California, reported the Associated Press.
Dr Richard Besser, acting director of the CDC, said that preliminary tests found a match.
"We are not at the point of declaring a pandemic - we are at the point of trying to learn more about this virus," he told reporters.
"In Mexico, other influenza viruses are circulating there, so sorting out which cases are caused by swine flu, which are other viruses and which are co-infections will be very important public health information."
All eight patients in the U.S. have recovered and only one needed to be hospitalized.