Carter questions timing of U.S. accusations against Cuba

Rosalynn and Jimmy Carter and Fidel Castro watch a group of musicians and dancers outside the Latin American Medical School.

HAVANA, Cuba (CNN) -- Former U.S. President Jimmy Carter has urged anyone alleging that Cuba may be trying to develop biological weapons and share that technology with other nations, to visit Cuba for a firsthand probe.

Carter -- on a historic trip to Cuba -- didn't specifically mention any accusers. But the Bush administration has alleged that the island nation is trying to develop biological weapons and is sharing that expertise to countries hostile to the United States.

White House Press Secretary Ari Fleischer on Tuesday reiterated the administration's "concerns" over the sharing of technology with countries hostile to the United States. (Full story)

Carter, who is scheduled to visit an AIDS center and a farm cooperative Tuesday, plans to make a speech Tuesday night that will be broadcast throughout Cuba.

In comments Monday, Carter said there were no allegations made or questions raised about possible terrorist activities by Cuba when he was briefed before the trip by officials from the State Department, intelligence agencies and the White House.

"I asked them specifically on more than one occasion: 'Is there any evidence that Cuba has been involved in sharing any information with any other country on Earth that could be used for terrorist purposes?'

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"And the answer from our experts on intelligence was 'no,'" Carter said.

"I think it's very significant, though, that this allegation was made, and I'm grateful just to come here," Carter said during a visit to the Center for Genetic Engineering and Biotechnology (Centro de Ingeniería y Biotecnología). The medical research institute develops vaccines for ailments such as AIDS and dengue fever, and works on other projects.

Carter said he chose -- with some reluctance -- to address the allegations because they "were made maybe not coincidentally just before our visit to Cuba."

Cuban leader Fidel Castro has vehemently denied the biological weapons charge, which Secretary of State Colin Powell repeated in an interview Sunday with Russian Television.

"We know that Cuba has been doing some research with respect to biological offensive weapons possibly, and so we think that it is appropriate for us to point out this kind of activity," Powell said.

But Carter questioned the timing of the allegations that came during his visit to Cuba.

"In the welcoming address at the airport when I arrived, your president publicly offered that any person who wanted to come and investigate any allegations concerning this bioterrorism issue would be free and welcome to come without restraint," Carter said, as Castro listened from the audience.

"My presumption and hope is that anyone who does have evidence of this kind will take advantage of this offer," he said.

Carter also commented on an allegation that Cuba was providing potential terrorist information to Libya and Iran.

"The understanding I had this morning is there's no relationship at all between Cuba and Libya in this field, and that there's a standard contract prescribed by the international community that any technology shared would be restrained from any illicit use."

"The relationship between Cuba and Iran in this respect is just in the initial stages and has not reached the point of technological development," Carter added.

Carter greets dissidents Oswaldo Paya, left, and Elizardo Sanchez at a Havana hotel Monday.

"My hope and my presumption is that Cuba will be very intensely concentrated upon enforcing that provision that would prevent any illicit or improper use of the technology which they share," he said.

The main goal of Carter's visit is to explore issues of mutual interest between the United States and Cuba in an effort to improve relations between the two longtime adversaries, which are separated by just 90 miles of water.

Carter praised the work of the science center, especially in the area of preventive health care and in cooperating with other countries on health programs.

"My hope is that in the future there can be close cooperation between the scientific and medical community in Cuba and that in my own country," he said. During a lengthy slide show, the Carters were told the center is working on 38 projects with 14 nations.

Contrary to President Bush's stance, Carter has been an outspoken advocate of ending the U.S. economic embargo against Cuba. The Bush administration says the embargo will not be lifted until Cuba shows progress toward democratic elections and improves its record on human rights.

Bush is to deliver a tough speech next week outlining the U.S. policy toward Cuba before traveling to Miami to honor Cuban Independence Day, aides have told CNN. (Full story)

At a school for social workers Monday afternoon, the highest-ranking current or former U.S. official to visit the island since Calvin Coolidge said that, though the two countries share a passion for baseball and good music, "there are some differences, as you know, in emphasis on certain elements of human rights." (Full story)

Earlier Monday, Carter ate breakfast with two leading Cuban dissidents.

One of the activists was Oswaldo Paya, coordinator for Project Varela. Paya and his supporters turned in more than 11,000 signatures Friday to the National Assembly, pushing for a referendum to ask voters if they support civil liberties such as freedom of speech and assembly, amnesty for political prisoners, the right to own their own businesses and a general election.

Also joining Carter for the meal at his hotel in Old Havana was veteran rights activist Elizardo Sanchez, who founded the Cuban Commission for Human Rights and National Reconciliation, one of the largest human rights groups in Cuba. Sanchez also is helping with Project Varela.

Accompanying Carter on the trip is his wife, Rosalynn.

-- CNN Correspondent Ed Lavandera contributed to this report.