Top Senate negotiators announced agreement Thursday on a $1.1 billion emergency funding measure to battle the Zika virus. That's less than President Barack Obama's $1.9 billion request but is expected to get sweeping support in a vote next week.

Washington Democrat Patty Murray told reporters that she still prefers Obama's proposal but has reached agreement with Roy Blunt, R-Mo., on the smaller measure, which is likely to be added next week to a bill funding veterans and transportation programs.

The administration requested emergency funding to battle Zika in February but Republicans controlling Congress have been slow to react, and instead forced the administration last month to tap more than $500 million worth of unspent Ebola funding to battle Zika. The compromise measure fails to restore most of that money.

"I have pushed for the $1.9 (billion) since the beginning. I think it's the right package,' Murray said. "But I have reached an agreement with Blunt  on what we can put into a package and we'll have a vote on it."

The Zika virus can cause microcephaly, a severe birth defect in which babies are born with abnormally small heads. It is spread by mosquitoes and sexual contact and is likely to spread more widely during mosquito season.

Aides to both Democrats and Republicans said the Blunt-Murray proposal is likely to easily pass the Senate, though Sens. Bill Nelson, D-Fla., and Marco Rubio, R-Fla., are demanding a vote on the full $1.9 billion administration request. No. 2 Sen. Republican John Cornyn of Texas is likely to offer an alternative that is financed with spending cuts elsewhere in the budget.

The Senate move is likely to set up a conflict with the House, where GOP leaders are likely to press for a much smaller amount and pay for it by cutting other programs or using leftover Ebola money that was passed at the end of 2014.

Across the Capitol, at a hearing called by House Democrats, Dr. Anthony Fauci of the National Institutes of Health, acknowledged, "It is very difficult to get people to invest in something that hasn't happened yet."

Federal health officials are not predicting widespread outbreaks of Zika in the continental United States. The Centers for Disease Control and Prevention reports more than 500 case of Zika in the continental United States, all of which are related to overseas travel.