By Michael Hernandez

WASHINGTON

With mosquito season quickly approaching for most of the continental U.S., the White House warned Wednesday that the Zika virus threat may be worse than originally thought.

Concerns over the mosquito-borne virus’ spread in the U.S. “have only increased” since the start of the year due to new information about its severity, spokesman Josh Earnest told reporters.

In addition to discovering that Zika's sexual transmission is more prevalent that originally thought, Earnest said that the effects on fetal brain development are “likely starker and more serious than first understood.”

In the U.S., the swath of land that the mosquito, aedes aegypti, which carries the virus will cover, “is significantly broader than our initial estimate,” he added.

The Obama administration in February requested $1.9 billion from Congress to support efforts to combat the spread of the virus, but lawmakers have yet to act on the proposal.

Since the request was made, “Congress has done nothing,” Earnest said.

The Obama administration is planning to repurpose approximately $600 million earmarked for last year’s efforts to combat the spread of Ebola, and use it instead to fight the spread of Zika at home.

But that alone is “insufficient” to fully combat Zika, Earnest said, noting that it is a “temporary fix” until Congress acts on the looming health crisis.

“We do have an opportunity to prepare for the Zika virus, but Congress has completely abdicated their (sic) responsibility to follow through” on the administration’s proposal Earnest said. “It's time for Congress to do its job for a change.”

"At some point, they're going to have to choose whether or not their animosity toward President [Barack] Obama trumps their desire to try to protect pregnant women in their states from this terrible disease," he added.

There have been 664 confirmed cases of Zika in the U.S. and its territories, according to the Centers for Disease Control and Prevention.

None of the cases on the U.S. mainland have been locally acquired, the organization said. Zika is usually not fatal but it can cause a rash and flu-like symptoms.

The virus has also been linked to the birth defect microcephaly, particularly in Brazil, prompting the World Health Organization (WHO) to declare a public health emergency.

WHO data indicates that local Zika transmission has been documented in at least 55 countries and territories from January 2007 to March 3 this year.

Cuban media reported last month that a woman who had never been abroad had the first confirmed case of Zika infection on the island nation.

Cuba lies just 144 kilometers (90 miles) from the U.S. mainland.

Although 80 percent of cases do not result in any symptoms, WHO officials estimate that 1.5 million people so far have been infected in Brazil alone.