MIAMI (CNN) -- Federal officials will try again on Wednesday to obtain written
                  assurances from Elian Gonzalez's Miami relatives that the boy will be handed over if
                  the family fails to win an appeal.

                  The relatives are challenging a lower court ruling that the U.S. Immigration and
                  Naturalization Service has the authority to reunite the 6-year-old boy with his father in
                  Cuba.

                  "Under federal immigration law and INS procedure, the government routinely
                  requests written assurances that individuals paroled into the United States will
                  comply with the terms of their parole," said INS spokeswoman Karen Kraushaar.
                  She said the government was asking Elian's great-uncle Lazaro Gonzalez to sign
                  the following agreement:

                  "That he will cooperate with an orderly transfer of Elian Gonzalez in the event of an
                  adverse ruling by the U.S. Court of Appeals and barring emergency injunctive relief
                  from the Supreme Court."

                  Parole could be revoked Thursday morning

                  The INS sent a letter Monday night warning the boy's great-uncle of the consequences
                  of not signing such an assurance.

                  "Without a specific written commitment, ... we have no choice but to move forward
                  with the termination of Elian's parole as of Thursday, March 30, 2000 at 9 a.m.," the
                  letter said.

                  The government letter did not indicate when or how federal authorities will arrange
                  for the transfer of Elian's custody.

                  Lazaro Gonzalez's daughter told CNN that she would not sign such a paper.

                  "Honestly, I would not want my father to sign that. To me, that's betraying Elian," said
                  Marisleysis Gonzalez on CNN's "TalkBack Live.

                  Marisleysis Gonzalez also said that even if her family loses in court, the only person
                  they would turn the boy over to is his father, and only at their home in Miami.

                  "I would like his father to come and pick him up," Marisleysis said. "Because I know
                  he's safe and I know that I put him in good hands. I will not give this little boy to anybody."

                  Her family's attorney's met with INS officials earlier Tuesday.

                  "They said sign the piece of paper or we're taking the kid," said the Gonzalez family's
                  spokesman, Armando Gutierrez.

                  The family could ask for a stay, pending how the appeals court rules. But if they are
                  turned down, that would give another green light to the INS to return the boy to Cuba.

                  An 'excuse to arrest Elian'

                  But INS spokeswoman Kraushaar said officials are concerned for the child, and that
                  the agency is trying to "resolve this matter in a way that avoids additional trauma to
                  him."

                  "It has been nearly 12 weeks since the commissioner's decision, and four months since
                  Elian was separated from his father and lost his mother," Kraushaar said. "As District
                  Court Judge Moore said in his ruling last week, 'Each passing day is another day lost
                  between Juan Gonzalez and his son.'

                  "We continue to urge everyone involved to work together to understand, respect and
                  uphold the bond between parent and child and the laws of the United States," she
                  added.

                  Monday's INS letter came on the same day that the 11th U.S. Circuit Court of Appeals
                  agreed to hear an appeal by the Miami relatives to reverse a lower court decision that
                  allowed the Justice Department, which oversees the INS, to return the boy to Cuba.

                  The court gave the relatives until April 10 to file their appeal, and oral arguments in the
                  case have been scheduled for the week of May 8 in Atlanta.

                  Spencer Eig, the family's lead attorney, said Monday the Miami relatives were not in
                  violation of the government's ultimatum and said the Justice Department is looking for
                  an "excuse to arrest Elian."

                  "INS has asked Lazaro Gonzalez to sign a piece of paper guaranteeing that he'll do
                  anything they tell him to do," Eig said. "No attorney would ever advise a client to sign
                  such an open-ended guarantee."

                  Havana calls for 'drastic action'

                  Elian was found clinging to an inner tube off the Florida coast last November 25. He
                  was one of three survivors of a shipwrecked immigration attempt from Cuba, that left
                  his mother, stepfather and nine others dead.

                  Since the start of the case, the Miami relatives and their supporters among the
                  Cuban exile community have contended that the boy would face a miserable future if
                  he was returned to Cuba.

                   But Castro, saying the boy has been "kidnapped" by his great-uncle Lazaro
                   Gonzalez and what he terms the Miami "mafia," has mobilized huge protests in
                   Cuba to call for his return.

                  In a speech on Sunday, Castro said some Cubans were now calling for drastic action
                  to obtain Elian's return, up to and including an armed rescue mission.

                  Other views cited by Castro as "spontaneous opinions from the people" called for a
                  blockade of the U.S. diplomatic mission in Havana and an opening of Cuba's frontiers
                  to unleash a flood of migrants toward the United States.

                  Castro said subjecting Elian to the television interview was "monstrous and
                  sickening."

                  "You cannot do this without the authorization of the father," Castro said. "I sincerely
                  think that this boy is at risk in the hands of desperate people, and the government of
                  the United States should not be running this risk."

                   Producer Terry Frieden, Correspondent Susan Candiotti, The Associated Press and
                                    Reuters contributed to this report.