Brazil's president said Tuesday that the voices of hundreds of thousands of protestors across the country, angered by the cost of hosting sporting events such as the World Cup, must be heard.

"These voices need to be heard," Dilma Rousseff said in an address at the presidential palace. "My government is listening to these voices for change."

"My government is committed to social transformation," she added, hailing what she called the largely peaceful nature of the protests.

"The voices of the street want more citizenship, health, transport, opportunities," said Brazil's first female head of state, a former Marxist guerrilla who was jailed and tortured during the country's 1964-1985 military dictatorship.

More than 250,000 people, most of them young, took to the streets of major cities Monday in the biggest social protests in 20 years to rail against the $15 billion being spent on the ongoing Confederations Cup and next year's World Cup to the detriment of investment in health and education.

"My government wants to broaden access to education and health, understands that the demands of the people change," Rousseff said.

The protesters also got the backing of Brazilian international Daniel Alves, who is preparing for Wednesday's Brazil-Mexico Confederations Cup clash in the northeast city of Fortaleza.

On his Instagram online photo-sharing service account, he posted a picture of a giant eye with yellow and green colors, as well as the motto of the national flag: "Order and Progress."

"Order and Progress without violence for a better Brazil, a peaceful Brazil, an educated, healthy, honest and happy Brazil," he wrote.