Ending his landmark trip to Cuba, former President Jimmy Carter on Friday urged sweeping changes in U.S. policy toward Cuba, as well as openings toward democracy within Cuba.

Carter told a news conference he'd like to see cooperation on bioterrorism, and that he would send his impressions Saturday to the White House and the State Department. President Bush is scheduled to speak Monday in Miami on American policy toward the communist country.

Carter said he recognizes "that after 43 years of misunderstanding and animosity that a brief trip cannot change the basic relationships between our peoples. But my hope is that in some small way at least, our visit might improve that situation in the future."

Undersecretary of State John Bolton said before Carter's trip that Cuba has provided biotechnology to "other rogue states" and the United States is concerned the information could support biological warfare programs.

Carter told to CNN that he stood by comments saying he had been told by administration officials that the United States had no evidence the communist country was transferring technology that could be used for terrorism.

"I believe it's true; that's what I was told," he said. "No one ever raised any question to me about bioterrorism, knowing about that I was coming here and the purpose of my visit."

Carter said he presumed that any evidence of Cuba's involvement in terrorism would be revealed, and noted that Cuba had said it would be open to sending an investigative team to Cuba.

"And I presume they'll take advantage of that as well," Carter said.

Carter told the news conference that better cooperation would ensure that Cuba's medical agreements with other nations are monitored to make sure that the ability to produce hepatitis B vaccine or meningitis B vaccine does not lead to this sort of activity for biological weapons.

Bush's speech in the heart of the Cuban exile community in the United States is expected to announce a hardening of policies toward Cuba, and appears to be a response in part to Carter's visit.

In the first visit by a serving or former U.S. president since Fidel Castro took power in 1959, Carter urged the communist leader to embrace democracy while calling on the Bush administration to drop the 40-year-old trade embargo against Cuba.

From Cuba's highest leaders to its most modest citizens, Carter had a reception fit for a pope.

There were chants of "Cahr-TEHR! Cahr-TEHR!" from villagers who lined the unpaved streets of small towns he visited. And for the first time since the 1998 visit of Pope John Paul II, Cuba's tightly government-controlled media published a long, word-by-word text of a foreign visitor preaching a distinctly noncommunist creed.

Castro honored Carter by allowing an unusual uncensored speech Tuesday to be broadcast over state radio and television networks. On Thursday, the Communist Party newspapers printed Carter's remarks, including the assertion that Cuba does not meet international treaty definitions of democracy as well as a call for the end of the U.S. embargo of the island.

Also Thursday, Carter met at the house of a U.N. official with 23 dissidents, one of whom had been freed from prison less than two weeks ago.

Carter first met alone with Vladimiro Roca, who was freed May 5 after nearly five years in prison for demanding changes in Cuba's communist system. He then met separately with two larger groups.

Carter "recommended unity among us, that we in the opposition join together," said Julio Ruiz Pitaluga, 76, who spent 23 years behind bars as a political prisoner.

Cuba's divided dissidents are united only by their common opponent: Castro's government. Some favor a free market, others want a socialism distinct from that of Castro. Some are politicians, others are professionals who found they did not fit into a system run by one party.

Several dissidents organized a petition drive and say they gathered more than 11,000 signatures to seek a national referendum on rights such as free speech, free association and free enterprise. Carter promoted that effort, the Varela Project, during his speech on Tuesday.

"His words at the university were historic," said Rene Gomez Manzano, who was imprisoned along with Roca but released earlier.

Manzano said that the publication of Carter's criticism "is something very different from what the people have become accustomed to hearing during the chill of 43 years," referring to Castro's time in power.

Thursday's newspapers also included the text of responses from Castro loyalists such as national student leader Hassan Perez, who charged that the backers of the Varela Project were "tied to a mafia" in the United States.

Justice Minister Roberto Diaz Sotolongo said backers of the petition "represent only 0.01 percent of the population," and added, "We know that the government of the United States, and especially the U.S. Interests Section in the country, have a role in this."

But he called the petition drive itself "proof of how democratic our system is."

The Bush administration has rejected Carter's call for an end to the trade embargo against Cuba. Bush is now the 10th president to use the sanctions to try to topple Castro; only Carter moved strongly toward ending them.

Bush is expected to outline a new Cuba policy Monday that would likely increase aid to dissidents, promote independent business and try again to overcome Cuban jamming of U.S. government stations.

Carter told reporters Friday that the dissidents he met with on Thursday told him a plan to increase U.S. government financing for their efforts could undermine their work by giving the Castro government something it can use to discredit them.

"They thought this would put an undeserved stigma on their actions," Carter said.