WASHINGTON – Iran halted its nuclear weapons development program in the fall of 2003 under international pressure but is continuing to enrich uranium, which means it may still be able to develop a weapon between 2010 and 2015, senior intelligence officials said yesterday.

That finding, in a new National Intelligence Estimate on Iran, is a change from two years ago, when U.S. intelligence agencies believed Tehran was determined to develop a nuclear capability and was continuing its weapons development program. It suggests that Iran is susceptible to diplomatic pressure, the officials said.

“Tehran’s decision to halt its nuclear weapons program suggests it is less determined to develop nuclear weapons than we have been judging since 2005,” states the unclassified summary of the secret report, released yesterday.

Officials said the new findings suggest that diplomacy has been effective in containing Iran’s nuclear ambitions, although President Bush’s national security adviser, Stephen Hadley, said the risk of Iran acquiring a nuclear weapon remains ” a serious problem.”

The estimate suggests that Bush “has the right strategy: intensified international pressure along with a willingness to negotiate a solution that serves Iranian interests, while ensuring that the world will never have to face a nuclear armed Iran,” Hadley said.

The finding comes at a time of escalating tensions between the United States and Iran, which Bush has labeled part of an “axis of evil,” along with Iraq and North Korea. At an Oct. 17 news conference, Bush said “if you’re interested in avoiding World War III, it seems like you ought to be interested in preventing them [Iran] from having the knowledge necessary to make a nuclear weapon.”