(CNN) -- Brazilian relatives of a 9-year-old boy, caught in an international custody battle with the child's father, will not file any further appeals after the Brazilian Supreme Court ruled against them, their attorney told CNN Wednesday.

The family is just looking for a peaceful handover of Sean Goldman to his father, attorney Sergio Tostes said, and plan on starting dialogue to allow the transfer to happen immediately.

The chief justice of the Brazilian Supreme Court ruled Tuesday in favor of David Goldman, who had been battling the family of the boy's deceased mother for custody. The ruling by Chief Justice Gilmar Mendes will reunite Sean with his father. Last week, a lower court unanimously upheld a decision ordering that Sean Goldman be returned to his father in New Jersey.

David Goldman arrived in Rio de Janeiro to reunite with his son, but one Supreme Court justice issued a stay, ordering Sean to remain with his Brazilian relatives until the high court could consider the case. Mendes' decision lifted the stay.

This week the U.S. State Department issued a passport to Sean, given to his father, so that he can travel back to the United States, spokesman Philip J. Crowley said Wednesday.

"Our embassy in Brasilia, our consulate in Rio de Janeiro, many people have been up through the night just to provide support to the Goldman family, to maintain contact with the Brazilian government ... as we, hopefully, come to the end of this process and look forward to the reuniting of Sean Goldman with his father, David," Crowley said.

The regional court decreed the boy must be handed over by 9 a.m. (6 a.m. ET) on Thursday.

"Sean is very sad because it is not and has never been his desire [to return to the United States]," his grandmother, Silvana Bianchi, told CNN. "He got especially disappointed about not having the right to speak in his own country [about] what he wanted for himself ... They are sending the boy to the United States without the right to defend himself. Where is the Brazilian constitution?"

Bianchi was initially expected to appeal. But Tostes said Wednesday the family wants to act in the boy's best interest, and he was meeting with an intermediary to arrange the handover. He said he would like Bianchi to meet with David Goldman so she can tell him what Sean likes to eat, what he enjoys doing and other details.

Asked whether she would accompany Sean on the flight to the United States, Bianchi would only say Tostes is negotiating what is best for the boy.

Upon hearing the family would file no further appeals, Rep. Chris Smith, R-New Jersey, said, "This is not good news. This is great news."

The custody battle began in 2004, when Goldman's wife, Bruna Bianchi, took their then-4-year-old son from their home in New Jersey to Rio de Janeiro for what was to have been a two-week vacation. She never returned, instead remarrying there and retaining custody of Sean. She died last year in childbirth.

Goldman has argued that as the sole surviving parent, he should be granted custody.

The Bianchi family maintained it would traumatize Sean to remove him from what has been his home for five years.

The custody battle garnered much media attention and spilled over into the political arena as well.

U.S. Sen. Frank Lautenberg, D-New Jersey, had placed a hold on a trade bill that would have benefited Brazil to the tune of $2.75 billion, but he lifted it after the court's ruling, spokesman Caley Gray told CNN.

The bill in question, which sailed through the Senate after the senator dropped the hold, provides export tariff relief to 130 countries, of which Brazil would be the fifth largest recipient, Gray said.

Lautenberg's hold was designed to exert additional pressure on Brazilian authorities to abide by the court order to return Sean to his father, he said.

Silvana Bianchi told CNN Wednesday it was "very sad, a country that exchanges children for economic agreements."

While the chief justice was still studying the case, Brazilian Attorney General Luis Inacio Adams said the executive branch of Brazilian government sided with Goldman.

"Once we stop cooperating and start breaking our treaties and international obligations, Brazil risks the chance of not having its own requests in the matters regarding international judicial help granted, based on the principle of international reciprocity," Adams said Monday.

"Not releasing the minor into the custody of his father could bring sanctions against Brazil," he added. "It could damage Brazil's image before the international community."

CNN's Mariano Castillo and Adam Reiss and journalist Luciani Gomes contributed to this report.