Brazilian President Dilma Rousseff led two dozen ministers on a campaign Friday to form what one official called an "army" of children against the Zika-carrying mosquito.

Brazil is at the heart of an international scare over Zika, which has been linked to the serious birth defect microcephaly in babies born to infected women.

With no cure to microcephaly or vaccine against Zika, Brazil's government has ordered out tens of thousands of troops and health workers in a door to door campaign to clean up stagnant water pools where mosquitoes breed.

Joining that push, Rousseff and 25 ministers from her sprawling cabinet urged children to form the next wave.

"The school can create a little army of children, adolescents and youths that will go home and mobilize the parents," Agriculture Minister Katia Abreu said in a visit to a school in Goiana, in the west.

She said each tiny "soldier" would be armed with a supply of insecticide to take home.

But at another school, Rousseff said the most important tactic in the government's declared war on mosquitos is to clear up water pools.

"Fifteen minutes a week is all you need," Rousseff said in a speech in front of children in the north-eastern city of Juazeiro.

"Talk with your parents, talk with your neighbors," she urged. "Because look how things are: if a mosquito produces 1,500 eggs and if there's a street with let's say 20 houses, then if 19 houses fight the mosquito and one doesn't, that's enough for the mosquito to have a party."

Rousseff said that protecting pregnant women from the risk of Zika is to protect "the future of this country."