U.S. Sen. Charles Schumer says Congress must return to Washington to take up emergency funding to combat the Zika virus.
The New York Democrat said Sunday that ongoing work on a vaccine could be jeopardized unless lawmakers end their current recess early and approve a $1.9 billion emergency Zika funding bill.
Schumer says he made his request in a letter to House and Senate leadership.
State officials say there have been 537 confirmed cases of Zika in New York so far, though all appear to be connected to travel to affected areas.
Schumer says lawmakers would only have to return to Washington for a single day to approve the funding.
Congress is now scheduled to reconvene in September.