Florida Sen. Bill Nelson said he sent a letter to Senate Majority Leader Mitch McConnell Tuesday asking him to unanimously pass a Zika funding bill that is stalled in the Senate.

"I sent one to McConnell today saying that he doesn't have to reconvene the Senate. They have nine more pro forma sessions and the Senate rules allow by unanimous consent that you can bring up the ...[Senate bill], pass it by unanimous consent and send it down to the House, putting the pressure of the House for that," Nelson told a reporter at the State Dinner for Singapore Tuesday evening.

"But if they don't understand that this is now a crisis, with what has just happened in Miami, then they've got really - they are putting their heads in the sand," Nelson added.

The Democrat, whose state has the first mosquito-transmitted Zika in the country, claimed it would take a Zika outbreak in Kentucky to get the GOP senator to move on the bill.

"[W]ait until a mosquito bites one of the people who is traveling to Kentucky and then he gets a transmitted case in Kentucky, then we'll get action," Nelson said.

Congress adjourned for seven weeks last month without approving a $1.1 billion funding package to help federal agencies fight the virus.

While it passed the House, Democrats blocked it in the Senate because of objections to riders on the Confederate flag and stripping Planned Parenthood of funding. Democrats also say they want the full $1.9 billion President Obama asked for in February.

Florida health officials have found 15 cases of mosquito-transmitted Zika in a neighborhood north of Miami's downtown. More than 1,600 cases have been found throughout the U.S., but almost all of them are people who traveled to one of the 50 countries where Zika is spreading.

While the virus can cause a mild illness in one out of five people it infects, it also causes the birth defect microcephaly.

The Centers for Disease Control and Prevention on Monday issued a travel warning for pregnant women to stay away from the Miami neighborhood where the Zika cases have been found. CDC Director Tom Frieden told reporters on Monday that aggressive efforts to kill the mosquitoes "don't seem to be working as well as we would have liked."