Iranian President Mohammad Khatami (search) said Tuesday he was saddened by the 2001 terror attacks on the United States, but he condemned the U.S. response — the invasion of Iraq — saying that war and terror have the "same roots."

Khatami was speaking at a conference in Paris, where he also met President Jacques Chirac (search) for talks on Iran's nuclear program and the situation in Lebanon.

On the nuclear issue, Khatami said he was "certain that today we are closer to a solution than we were a while back."

"We have taken some positive steps," he said, expressing hope for "even more significant progress" at further talks at the end of this month.

He said Iran (search) had proposed "an overall plan" to resolve the nuclear issue, and "the European reaction, particularly that of France, has been very open."

France, Germany and Britain are trying to negotiate a permanent suspension of Tehran's efforts to enrich uranium, which can be used both as fuel for energy or in nuclear weapons.

Iran says the current freeze is short-term. The United States fears Iran's nuclear program is aimed at producing weaponry, but has softened its tone to see if the European diplomatic approach can work.

Khatami was in Paris at the behest of the U.N. Educational, Scientific and Cultural Organization, which was holding an international conference to take stock of progress in its program to promote dialogue among peoples of the world. The Iranian and Algerian President Abdelaziz Bouteflika were keynote speakers at the tightly guarded event.

Khatami said fallout from the 2001 attacks — which he referred to as "terror in its most horrendous form" — made clear an urgent need for dialogue among civilizations to avoid "an escalation of hatred, terrorism, war and carnage."

Alluding to the United States, he condemned "pre-emptive war ... by a power with all the resources in its hands that entitles itself to attack a nation, as we've seen in Iraq."

"War and terror are from the same roots," he said. Both seek "goals that are restricted, limited," and both are "evil."

Khatami, who came to Paris from Austria, was making what he said was his last foreign trip before leaving office at the end of the second of two four-year terms. He was first elected in 1997.

Considered a moderate, Khatami's power to effect reforms has been limited by the grip of hard-liners on the Islamic Republic.

Several hundred protesters took part in a demonstration in Paris against Khatami's visit. Some held posters showing the faces of political prisoners and signs reading: "Welcoming Khatami is to encourage stonings and executions in Iran."

In an interview published Tuesday in the French daily Le Figaro, Khatami reiterated Iran's refusal to renounce the peaceful use of nuclear technology.

"We are ready to give an objective guarantee that we are not trying to develop nuclear weapons," he was quoted as saying.

He said he took seriously the possibility of an American strike against Iranian nuclear facilities, "but that appears to us to be unlikely. Such an attack would not only be bad for Iran but also for the attackers," adding that he hopes that the Americans "remain rational."

"But in the face of any form of irrationality, we are ready to defend ourselves," Khatami said.