Four more Florida residents have been infected with the Zika virus, making 21 cases in the U.S. likely transmitted by mosquitos.

Florida Gov. Rick Scott announced the additional cases Tuesday afternoon, saying they all are within the same small neighborhood in the Miami-Dade area where Zika has been spreading locally.

That neighborhood is thought to be the only area in the U.S. where Zika is spreading via mosquito so far. The other nearly 2,000 cases in the country are travel-related.

"All four of these cases are located in the same, small area of Wynwood that is less than one square mile," Scott said.

Scott added that he has allocated more than $26 million in state funds to fight Zika, but he urged Congress to approve more emergency funding.

"Every day that passes that Congress and the president fail to come to an agreement hinders our national response to Zika," Scott said. "This is not only an issue affecting us here in Florida — this is a national issue."