US Health and Human Services Secretary Sylvia Burwell said there was "a public health emergency of national significance" in Puerto Rico, with Zika posing a particular threat to pregnant women and their children.

"This administration is committed to meeting the Zika outbreak in Puerto Rico with the necessary urgency," she said in a statement, without providing further details about the type of support it may provide.

The declaration means the island can now apply for emergency funding and appoint staff to assist in mosquito control efforts, outreach and Zika education campaigns.

Puerto Rico's health department reported Friday that 10,690 people had been infected with the mosquito-borne virus in the last seven months. More than 1,900 of those cases were in the last week alone. Puerto Rico Governor Alejandro Garcia Padilla thanked federal officials for responding to his request to declare an emergency.

"The threat of Zika to future generations of Puerto Ricans is evident, and I feel a responsibility to do everything that is within my reach to make sure we fight the spread of the virus," he said in a statement.

Danger to pregnant women

Zika was first detected in Brazil last year, and has since spread rapidly through South America and the Caribbean. More than 1,000 pregnant women in Puerto Rico have been infected. The US surgeon general said this week he expected 25 percent of the territory's population to be infected with Zika by the end of 2016.

While most people who contract Zika suffer no symptoms, the virus is considered to be particularly dangerous for pregnant women because it can cause birth defects including microcephaly - a condition in which infants are born with small heads. It has also been linked to a temporary paralysis condition known as Guillain-Barre.

The virus is mainly transmitted by mosquitoes, but it can also spread via sexual contact. In July, the US reported its first locally transmitted cases of Zika in the southern state of Florida.

nm/cmk (Reuters, AFP, AP)