A new U.S. intelligence estimate says it is not clear that Iran is determined to produce nuclear weapons. The estimate says Iran stopped nuclear weapons development four years ago, but adds that Tehran is keeping its options open. VOA Correspondent Gary Thomas reports from Washington.

A new National Intelligence Estimate on Iran's nuclear capabilities and intentions says international pressure and scrutiny caused Iran to stop work on nuclear weapons in late 2003, and the work had not resumed as of mid-2007.

But the report adds that Iran appears to be keeping open the option of building a nuclear weapon. It says Iran continues to produce enriched uranium. The estimate says, Iran is not likely to have enough weapons-grade highly enriched uranium for a bomb until late 2009 at the earliest.

The key findings of the estimate, which represent the highest collective judgments of the U.S. intelligence community, were released Monday.

The new assessment differs sharply in some respects with a 2005 National Intelligence Estimate on Iran. In 2005 the intelligence agencies said Iran was determined to develop nuclear weapons. The new estimate says it now appears Iran is less determined to produce nuclear weapons than previously believed.

Nevertheless, it adds, it would be difficult to persuade Iran's leadership to give up any ambitions to be a nuclear power.

In a written statement, National Security Advisor Stephen Hadley says the new estimate has some positive news. He said it confirms the Bush administration strategy of keeping up international diplomatic pressure on Iran.

Hadley says it underscores that Iran's nuclear ambitions remain a very serious problem.

Senate Majority Leader Harry Reid, who had asked the White House to produce the latest estimate, says it shows the need for engaging Iran on the nuclear issue.

"We should be having a surge of diplomacy with Iran," he said. "And based upon this [estimate], I think it would be a pretty good idea."

The United States has been trying to forge a consensus among the five permanent members of the U.N. Security Council for new sanctions on Iran for its alleged nuclear weapons ambitions.

Iran has insisted that it only seeks to develop nuclear energy for peaceful, non-military use.