WASHINGTON (AP) -- The head of the government's fight against the Zika virus said that "we are now essentially out of money" and warned that the country is "about to see a bunch of kids born with microcephaly" in the coming months.

Friday's warning from Centers for Disease Control and Prevention Director Thomas Frieden came as lawmakers start to sort out a stopgap government funding bill that is being targeted to also carry long-delayed money to battle Zika.

Zika is spreading more widely in the U.S. and can not only cause microcephaly - in which babies are born with grave brain defects - but other problems that the country will face for decades.

Frieden said funding delays have slowed long-term studies of the disease and production of new tests for it. "We haven't been able to get a running start" on a long-term battle against Zika, he said.

Frieden added that "we don't like to see" the use of pesticides such as Friday morning's spraying of naled, in Miami Beach. But, he said, new technologies for the application of such toxic chemicals are safe for humans. The two localized mosquito-borne outbreaks in Miami are "quite difficult to control," Frieden said, adding that the type of mosquitoes that spread Zika "are the cockroach of mosquitoes."

President Barack Obama in February requested $1.9 billion to battle Zika, but Republicans controlling Congress acted slowly on the request. A Capitol Hill fight this summer stalled the Zika aid. Republicans attached restrictions on any of the money going to affiliates of Planned Parenthood in Puerto Rico. Democrats objected and blocked the $1.1 billion measure.

Now, negotiations are underway to break the impasse over Zika and add it to the only piece of legislation that has to pass Congress before the election: A stopgap funding bill to avert a government shutdown on Oct. 1.

Democrats and the White House have greater leverage now since their approval is needed for the stopgap spending bill, and Republicans are signaling they'll likely lift the restrictions on delivering contraception, treatment and care through Planned Parenthood, an organization that many Republicans loathe since it is a major provider of abortion.

A bipartisan consensus is emerging to fund the government through mid-December, though some House tea party conservatives are opposed and want a longer duration for the measure to avert a lame duck session of Congress.

Since February, Zika has spread more widely, and frustration is mounting from lawmakers representing affected areas.

"Look if we don't, then fire all of us," said Florida GOP Rep. David Jolly, whose state is bearing the brunt of the disease in the continental U.S. "If we can't get Zika funding by the end of September then we're nothing but a bunch of idiots up here."

"I think we'll look at this delay in time and say, 'How could they have waited so long?' This was so urgent. It was the very definition of an emergency," Frieden said. "Not only is this unanticipated, it's unprecedented. It's potentially catastrophic, and it's certainly that for the kind of brain damage we're seeing."

Frieden noted that it is extremely unusual to have a new cause for a severe birth defect and that the health care system will be grappling with the effects of Zika for years to come. While microcephaly is the most immediate result of the outbreak, Frieden noted that infants are having problems swallowing and with their vision and hearing.

"We don't know what congenital Zika syndrome will look like," Frieden said. "We will likely be dealing with this for decades to come."

MEXICO CITY (AP) — Mexican health authorities approved the first vaccine to gain official acceptance for use against the dengue virus, which sickens about 100 million people every year, mostly in Asia, Africa and Latin America.

The federal medical safety agency said Wednesday the vaccine has undergone testing on over 29,000 patients worldwide. It said the vaccine's manufacturer had proved its safety and effectiveness, but did not name the drug.

In a separate statement, the Lyon, France-based Sanofi Pasteur identified the vaccine as Dengvaxia.

Mexico said the vaccine is aimed at people ages 9 to 45 and will be used in areas where the disease is endemic.

According to a World Health Organization report published in late 2014, the vaccine had an average rate of effectiveness of about 60.8 percent in protecting against the four strains of dengue currently circulating. Sanofi said its vaccine was shown to" reduce dengue due to all four serotypes (strains) in two-thirds of the participants," a figure similar to the 65.6 percent rate reported in a study published in September by the New England Journal of Medicine.

That is relatively low for a vaccine. Common vaccines like those for measles and polio are more than 95 percent effective.

But Dengvaxia appeared to be particularly effective in protecting people from the most extreme, potentially life-threatening form of the disease, known as dengue hemorrhagic fever, which can cause internal bleeding, shock, organ failure and death. That form of the disease seems to hit people who have already had one strain of dengue, and then suffer a subsequent infection by a different strain.

Because of that, Mexico said it planned to apply the vaccine in areas were exposure rates to at least one strain were 60 percent or more.

Dr. In-Kyu Yoon, director of the international Dengue Vaccine Initiative, said the drug "may potentially have a significant public health impact," but noted "we still don't know how much Sanofi will charge."

"It probably will work best in those regions and countries that have the highest rate" of dengue exposure, Yoon said.

Sanofi said in its statement that the drug "prevented 9 out of 10 cases of severe dengue and 8 out 10 hospitalizations due to dengue."

Dr. Cuauhtemoc Ruiz, chief of Pan American Health Organizations' immunization program, said that whether the vaccine will be widely used will depend on a cost-benefit analysis. Countries will have to weigh whether another treatment or simply spraying to reduce mosquitoes would prevent more illnesses and deaths for the same money.

Ruiz added that at least five other dengue vaccines are in clinical development.

Mexico's federal medical safety agency, known by its initials as Cofepris, said the vaccine could help prevent 104 deaths and 8,000 hospital admissions and save about $65 million in health expenditures annually. Mexico's Health Department declined to comment on whether the government would supply the vaccine to those who need it most in the country's largely poor, low-lying southern states.

WHO's report said it was unclear how long the vaccine would protect those who receive it.

Mosquitoes transmit the dengue virus. Symptoms include high fevers and severe muscle and joint pain. There's no specific treatment for dengue.