NEW YORK, Aug 3: The Bush administration officials have taken issue with a private arms-control group which had recently claimed that a new reactor being built in Pakistan is unusually large and could make fuel for up to 50 nuclear warheads a year, the New York Times said in a report on Thursday.

“We have consulted our experts and believe the analysis is wrong,” Frederick Jones, a spokesman for the National Security Council told the newspaper. “The reactor is expected to be substantially smaller and less capable than reported.”

The newspaper noted that the episode underscored the uncertainties usually surrounding nuclear intelligence.

In recent years, the government had come under fire for warnings of nuclear dangers that turned out to be false, most notably in the case of Iraq’s efforts, it added.

Critics say the analyses are often subject to political spin.

A large reactor could foreshadow a significant expansion of Pakistan’s nuclear arsenal, currently estimated at 40 to 50 nuclear weapons.

The Times recalled that the report last week by the private group came amid debate over the Bush administration’s proposed nuclear deal with India and raised fears that Pakistan was trying to speed ahead in a South Asian arms race.

The newspaper said that in interviews, federal officials said their own intelligence indicated that the emerging reactor appeared to be roughly the same size as the small one currently being used by Pakistan to make plutonium for its nuclear programme, and said the new model might be intended to replace the old one.

They spoke on the condition of anonymity because of prohibitions on the public discussion of secretive intelligence issues.

“This has been looked at for a long time and hasn’t generated a lot of hand-wringing,” a senior intelligence official said of the new reactor. “It could be a replacement,” he added.

According to the New York Times report, the United States closely monitors Pakistan’s nuclear work because President Pervez Musharraf’s government is considered to be the most unstable of the governments in countries having nuclear capability, and its relevant facilities are seen as prime targets for Islamic terrorists seeking nuclear weapons.