The entire Florida congressional delegation wants the federal government to give more funding to the state to fight the Zika virus, which is spreading by mosquito bites in a small area of Miami.

House and Senate lawmakers with both parties wrote to the Centers for Disease Control and Prevention on Tuesday to ask the agency to change its formula for allocating funding to fight the virus, which causes a mild illness and is linked to a birth defect called microcephaly.

It pointed to the CDC's recent allocation of an additional $16 million to 40 states and territories to fight Zika.

Of that $16 million, Florida gets $720,000, a portion that is not sitting well with the state's delegation.

"This amounts to a paltry 4.5 percent of funding made available, despite the fact that almost half of all confirmed non-travel cases of the disease in the continental United States have now been linked to mosquito transmission in Florida," the letter said.

In addition to the 15 cases identified in Miami's Wynwood neighborhood, there are 15 cases of sexual transmission of Zika in different parts of the country. There are more than 1,600 travel cases of Zika, where people got it in another country or territory where the virus is spreading.

The lawmakers did praise the CDC for working closely with local officials to contain the Miami outbreak and giving more than $8 million in Zika-specific funding to the state. However, because of the "potential for explosive spread of the virus," the agency needs to reconsider its allocation formula for the $16 million, the letter added.

The letter comes as lawmakers in both parties are battling over who is to blame for not approving funding for fighting the virus.

Congress adjourned last month but did not approve a $1.1 billion funding package to fight the virus. The package passed the House but Democrats in the Senate blocked it because of objections that include taking money from Obamacare to help pay for part of it and not including funding for Planned Parenthood centers in Puerto Rico.