Brazil's first elected leftist president took office today, pledging to ease the agony of countless impoverished and hungry people in South America's largest country, a fertile land the size of the continental United States.

Choking back tears as he spoke to an estimated 200,000 supporters, Luiz Inacio Lula da Silva said there was no excuse for hunger among any of Brazil's estimated 50 million poor. "If at the end of my mandate all Brazilians have the possibility to eat breakfast, lunch and dinner, I will have fulfilled the mission of my life," the former union leader and head of the Workers Party said.

Lula warned, however, that the task would be difficult. Brazil's weakened economy has produced double-digit inflation and a 35 percent loss in the value of its currency last year. "No one can reap the fruit before planting the trees," Lula said.

As Lula began to speak before Congress, supporters who jammed into a huge park outside danced and chanted, "Lula! Lula!" Then they fell silent, transfixed by the son of a dirt-poor farmer who dropped out of the fifth grade to shine shoes and sell peanuts. The scene was in stark contrast to previous Brazilian presidential inaugurations, when crowds never numbered more than 30,000.

Lula said he would fight inflation, reduce corruption, boost efforts to give land to the poor and negotiate hard with the United States over the terms of a hemisphere-wide free trade agreement.

Psychiatry professor Maria Aparecida Gussi and her 13-year-old daughter cried tears of joy during the speech. "All I want is a better Brazil for my children, and he's giving us that hope," Gussi said. "The hope that it will be better."

After the swearing-in and speech before Congress, Lula ascended a ramp to the presidential building and accepted from outgoing President Fernando Henrique Cardoso the green, blue and yellow presidential sash.

Leaders and representatives of 119 countries -- including presidents of seven other Latin American nations -- attended the inauguration.

The United States sent Trade Representative Robert B. Zoellick. He and Sen. Mike Enzi (R-Wyo.) met this morning for an hour with Antonio Palocci, Lula's finance minister.

"It was a listen-and-learn visit, in which the basic economic problems of Brazil were discussed," Zoellick said in a statement.

Presidents Fidel Castro of Cuba and Hugo Chavez of Venezuela watched from the front row of Congress as Lula was sworn in. Castro looked healthy and showed no signs of difficulty walking after recovering from a serious leg infection; Chavez was expected to be absent from his strikebound and politically riven country for less than a day.

Lula, 57, takes over from Cardoso in Brazil's first transition between two democratically elected presidents in more than 40 years. He is Brazil's 36th president.

The country's last leftist president, Joao Goulart, took power in 1961 after elected President Janio Quadros unexpectedly resigned. Goulart was overthrown in a military coup in 1964.

A former radical who had espoused socialism, Lula rose to fame in the 1970s as a major labor leader and dissident. He was jailed several times for opposing Brazil's dictatorship, which lasted until 1985. He won the presidency in a landslide in October on his fourth try since 1989.

Brazil's Luiz Inacio Lula da Silva, left, and running mate Jose Alencar, a textile tycoon, wave to a crowd of 200,000 supporters in Brasilia as they ride to Congress to be sworn in.