MSNBC STAFF AND WIRE REPORTS

MIAMI, Dec. 6 —  The boy at the center of a custody dispute affecting Cuban-U.S. relations turned 6 on Monday, with no sign that the controversy around him would be resolved soon. Cuban President Fidel Castro on Sunday vowed that “millions” of Cubans would protest outside the U.S. mission in Havana if Elian Gonzalez is not returned by Tuesday. Cuba also warned it might cancel the next round of immigration talks, set to begin next Monday.
    ELIAN, WHO was given a birthday party Sunday by Miami relatives who want to retain custody, was rescued Thanksgiving morning as he clung to an inner tube on the high seas. The child was one of three survivors of an overcrowded powerboat that sunk in a storm. Ten other Cubans died in the illegal attempt to reach Florida shores, including the little boy’s mother.
    After the boy’s father asked the Cuban Foreign Ministry to help him regain custody of his son, Havana accused the U.S. government of kidnapping for not immediately returning the child to his father and instead turning him over to Miami relatives the boy barely knew.
    The conflict threatens to derail U.S.-Cuban talks set for Dec. 13 in Havana, part of implementing the 1994 bilateral agreements that sought to stem the illegal refugee flow from Cuba. That summer, more than 35,000 rafters risked their lives crossing the Florida Straits before the two governments signed the accord.

‘A MATTER OF KIDNAPPING’

    The United States argues that the custody fight must be settled in Florida family court. “This is an issue that needs to be hammered out through the appropriate legal channels,” deputy White House press secretary Barry Toil said Sunday.
    But the Castro government is demanding the Clinton administration act return the child. “It’s not a matter of custody. It’s a matter of kidnapping a child. Who are the kidnappers? The U.S. authorities because they did not abide by international law, by American law, by Cuban law, by common sense,” said Ricardo Alarcon, parliament president and Havana’s chief negotiator with the United States.

PROTESTS OUTSIDE U.S. MISSION

    On Cuban state-run television, Castro said if the boy was not soon returned within 72 hours, there would be massive anti-American protests in Havana. Cubans protested in front of the U.S. government mission on Sunday, and another rally was planned for Monday.
    “Let’s see if they can resist the presence of our people here every day. Our Elian will return home!” Otto Rivero, the leader of Cuba’s Young Communist movement, told the 2,000 demonstrators.
    Waving Cuban flags, and shaking their fists, the protesters chanted “Long live Fidel!” “Down with the Yankees!” and “Clinton, ruffian, we want Elian!”
    The event was closely controlled by Cuban security agents, and there was no attempt to enter the U.S. mission.
    Alarcon threatened to cancel the upcoming immigration talks. “In order to have a serious fruitful meeting, Elian should be back home. Can you imagine the kidnappers coming down to Havana, to talk about what? To discuss what? What agreement? The agreement they are violating in every instance since that incident occurred?” said Alarcon.
    The United States and Cuba have held the talks every six months since signing the agreement which seeks to stop often-treacherous illegal immigration from the island. The agreement allows 20,000 Cubans a year to immigrate through legal channels while calling for the U.S. to repatriate illegal Cuban immigrants picked up at sea.

‘COMPLETELY IN VIOLATION’

     Alarcon told NBC News that Cuba is “interested in maintaining the agreement. We are serious. We respect what we signed but ... the U.S. is completely in violation of those agreements, the letter and the spirit of those agreements.”
    When asked if he’d feel untroubled facing U.S. negotiators next Monday if Elian had still not been reunited with his father, Alarcon replied, “Certainly not.”
     “I would feel comfortable demanding they return the boy and accusing them again of violating these agreements,” he said.
    Castro demanded the U.S. government return the boy within three days or face protests my much of the island’s population of 11 million.
    “They should be prudent, and before 72 hours, because if not, there are going to be millions of people in the street demanding the freedom of the boy, who will not stop until they send him back,” a visibly furious Castro said in comments broadcast on state TV early Sunday.

MORE SOLDIERS AT U.S. MISSION

    In an unusual move Sunday, the Cuban government stationed several dozen soldiers outside the U.S. Interests Section in Havana — the American government’s Cuban mission. The reason for the move was not clear; generally there are only about four soldiers outside the mission.
    “Our first priority is the welfare of the child,” said a State Department official in reaction to Castro’s warning. “We will not respond to threats made against the United States through the press,” the official said. However, he added, “we are in the process of responding to a diplomatic note sent to the United States by the Cuban government on November 25th.”
    According to Alarcon, embodied in the foundation of the bilateral agreement is denial of parole to illegal Cubans. Elian’s case proves that “they have not discontinued that policy,” Alarcon said.
    Alarcon also takes issue with the Cuban Adjustment Act, an American law that grants privileged status to Cubans over any other refugees. Under the act, any illegal Cuban reaching U.S. shores has a right to stay in the United States and can even apply for a green card within 24 hours of arrival.
    This special treatment, charged Alarcon, “is the source of the illegal attempts to enter the U.S. from Cuba ... the source of the smuggling business that’s going on at this very moment.”
    More than 30 Cuban Americans are currently in custody on the island, either convicted or awaiting trial on charges of immigrant smuggling.

    NBC’s Mary Murray in Havana and The Associated Press and Reuters contributed to this report.