The U.S. House of Representatives passed a Republican-backed bill Wednesday night to combat the Zika virus that the White House has already threatened to veto as inadequate. The bill, sponsored by Rep. Hal Rogers, R-Kentucky, chairman of the Appropriations Committee, would provide $622 million to fight the virus — less than a third of what President Barack Obama asked for three months ago. The measure next must be reconciled with a compromise Zika bill the Senate passed Tuesday, which would provide about $1.1 billion, or roughly two-thirds of what the White House wants. Sources in the congressional leadership told NBC News on Wednesday night that a final bill could be a long way off, since there isn't a clear path to compromise. But House Speaker Paul Ryan, R-Wisconsin, said the House bill "helps protect our people from the spread of Zika in the most direct way possible." "We will now work with the Senate to get the needed resources to the president's desk," he said. In threatening a veto Tuesday, the White House said the full $1.9 billion is needed to fully fund research and to counter the risk of the mosquito-borne virus, especially among pregnant women. The Infectious Diseases Society of America said in a statement: "The Zika threat to the continental United States is imminent with the approach of summer. State and local public health departments as well as biomedical researchers need robust resources now to protect our population from Zika and to develop vaccines, rapid diagnostics, and therapeutic agents." This story originally appeared on NBCNews.com.