The Senate approved $1.1 billion in funding to federal agencies for anti-Zika virus efforts a day after the House passed its own $622 million bill, setting up negotiations between the two chambers on what legislation will eventually end up on President Barack Obama’s desk, the Associated Press reported.

Both proposals offer less than the $1.9 billion in emergency funds Obama had requested earlier this year. Since then, the virus, which the CDC has determined can be spread through sexual contact and mosquitoes and cause severe birth defects such as microcephaly, has been contracted by more than 500 people in the continental U.S., 122 of them in Florida, according to the Miami Herald, all related to travel.

The differences in the proposal mainly lie in where the money would be coming from, as the House bill pays for the request by cutting funding provided for the 2014 Ebola outbreak. The Senate bill provides emergency funding, which doesn’t have to be offset with cuts. The House bill also limits the use of money to the current budget year, which ends Sept. 30, while the Senate funding would last through September 2017.

The White House has promised to veto the House proposal, saying in a statement the $622 million would be “woefully inadequate,” a sentiment echoed by CDC Director Tom Frieden.

"It's just not enough," Frieden said of the House measure to the Associated Press. "It doesn't give Americans the protections they deserve, and with every day of delay it gets harder to do this."

House Republicans said after their proposal was passed that the gap between the two chambers’ bills isn’t as wide as it would appear. Rep. Tom Cole, R-Okla., told The Hill Congress was likely to approve “hundreds of millions” in additional funding for the next budget year in the appropriations bill for HHS and other agencies.

“It will be very, very substantial,” Cole said. “Actually, by the end of this, if you add it all up, we’ll either be at or above the Senate’s total... It’ll be very comparable.”

Cole also noted the Obama administration already has nearly $600 million at its disposal for anti-Zika efforts, mostly from funding allocated to combat Ebola in west Africa.  

The White House’s Zika response website said the emergency funding would be used in a variety of ways, including direct assistance to the Latin American and Carribean countries most affected by Zika, accelerating vaccine development, mosquito abatement and providing resources to local public health departments.