Dr. Anthony Fauci, a top Obama administration doctor, urged Congress on Sunday to promptly agree to appropriate an additional roughly $2 billion to fight against Zika -- the latest in the back and forth between the White House and GOP-led House about funding against the deadly virus.

“We have to act now,” Fauci, director of the National Institute of Allergy and Infectious Diseases, told “Fox News Sunday.”

House Republican leaders have argued that the federal government has enough money now to fight the virus and that additional funding should come through the regular appropriations process this fall.

However, House Appropriations Committee Chairman Hal Rogers suggested last week that he would support immediate supplemental funding, with a White House request that includes a detailed spending plan.

“We can’t do it without the numbers,” the Kentucky Republican said Wednesday on Capitol Hill.

While Rogers also has tried to assure the public that Congress will not allow a public health crisis, he has suggested that the administration might not get all of the roughly $2 billion, which he has referred to as a “slush fund.”

“I disagree with that,” Fauci said, arguing the administration has presented Congress with a “project-by-project approach” and that it will also use money left from fighting the Ebola virus.

There has so far been no documented Zika infections in the United States from mosquitoes that carry the virus. But nearly 350 illnesses have been reported across all 50 states, each linked to travel to Zika outbreak regions, largely the Caribbean and Latin America. Thirty-two of the infected women were pregnant. The virus can also be spread through sex.

“The regular appropriations process takes too long,” Fauci said Sunday. “I don’t want to wait to have to develop a vaccine.”

The House agreed late last week on a bipartisan measure to speed up development of a treatment.

However, on Friday, Democratic Reps. Nita Lowey, N.Y.; Rosa DeLauro, Conn.; and Debbie Wasserman Schultz, Fla., urged Rogers to hold a special meeting on the administration’s request for emergency supplemental funding.

Under the rules of the Appropriations Committee, three members may request the chairman convene a special meeting. If the chairman fails to schedule such a meeting within seven calendar days, a majority of the committee members may convene a special meeting on their own.

A Zika infection causes only a mild and brief illness in most people. But in the last year, infections in pregnant women have been strongly linked to fetal deaths and devastating birth defects, mostly in Brazil, where 1,113 cases of related microcephaly have been confirmed since October.

The Associated Press contributed to this report.