Havana ? Touring a major biotechnology lab with Fidel Castro, Jimmy Carter on Monday took issue with Bush administration claims that the island nation has exported technological know-how to rogue states for use in biological weapons.

Bush administration officials, however, said they were standing by their assertions that Cuba has at least a limited biological warfare program and has shared such biotechnology with rogue states. One allegation says those states are Iran and Libya, Carter said.

A State Department official also said Monday that Carter was not briefed on the weapons issue because his briefing occurred before the allegations by Undersecretary of State John Bolton last week in Washington.

Early Monday, Carter met with two leading Cuban dissidents for a human rights briefing. Later, he toured the Center of Genetic Engineering and Biotechnology, telling Castro and Cuba’s top scientists that he specifically asked White House, State Department and intelligence officials during a recent briefing if Cuba was transferring technology or other information that could be used in terrorist activities.

“The purpose of this briefing was for them to share with us any concern that my government had about possible terrorist activities that were supported by Cuba,” he said.

“There were absolutely no allegations made or questions raised. I asked them specifically on more than one occasion if there was any evidence that Cuba has been involved in sharing any information to any other country on Earth that could be used for terrorist purposes.

“The answer from our experts on intelligence was, ‘no,”‘ Carter said.

The former American president the first former or current American leader to visit Castro’s Cuba noted the apparent contradictions and questioned their timing.

“These allegations were made, maybe not coincidentally, just before our visit to Cuba,” Carter said of Bolton’s concerns.

In remarks last week to the Heritage Foundation, a conservative research group, Bolton said he believes Cuba has at least a limited offensive biological warfare research and development effort.

“Cuba has provided dual-use biotechnology to other rogue states,” Bolton said. “We are concerned that such technology could support BW programs in those states. … We call on Cuba to cease all BW-applicable cooperation with rogue states and to fully comply with all of its obligations under the Biological Weapons Convention.”

Havana denounced Bolton’s allegation as a lie and promised Carter “complete access” to any Cuban biotechnology laboratory.

But Monday, Secretary of State Colin Powell repeated what Bolton said and added that it was not a new statement by the Bush administration.

“I don’t know what briefings President Carter received,” Powell told reporters traveling with him to Iceland to attend a NATO summit.

Otto Reich, the assistant secretary of state for the Western Hemisphere, told The Associated Press that Carl Ford, the assistant secretary of state for intelligence and research, had given some of the same information to Congress at a March hearing.

“We stand by every word of John Bolton’s speech,” Reich said.

President Bush plans to deliver a speech on Cuba next Monday before visiting the Cuban exile community in Florida. The speech appears to have been prompted, in part, by Carter’s visit to Cuba.