There have been 107 cases of Zika virus among U.S. travelers returning from Zika-infected areas, the U.S. Centers for Disease Control and Prevention said Friday.

The CDC also reported 40 locally acquired cases of the virus in U.S. territories. Thirty-five are in Puerto Rico, four are in American Samoa, and one is in the U.S. Virgin Islands.

CDC Director Dr. Tom Frieden said Puerto Rico is clearly the most affected area, with the potential for hundreds of thousands of cases of the virus.

The agency also said pregnant women should consider not traveling to the Summer Olympics in Brazil, calling the situation with the virus there "dynamic." This is in line with existing recommendations for pregnant women to postpone travel to areas where the virus is being transmitted.

There are nine cases of the Zika virus among pregnant women in the United States who have returned from travel to Zika-infected areas, the CDC said.

At least two pregnant women in the United States infected with the Zika virus have chosen to have abortions in recent months, the Centers for Disease Control and Prevention reported Friday, while two others have suffered miscarriages. One woman gave birth to an infant with serious birth defects, while two others delivered healthy infants. Two are still pregnant.