The leading reformist candidate in upcoming Iranian presidential elections said Monday that if elected, he would negotiate with the U.S but that Iran would not give up its nuclear program.

Speaking in his first news conference since declaring his candidacy, Mir Hossein Mousavi said if Barack Obama''s administration changes the U.S.''s policies toward Iran, Mousavi would be open to talks. But, in comments that echo other top Iranian officials, Mousavi said the country is still waiting to see how Obama''s administration differs from that of his predecessor.

"We will definitely negotiate with them. Why not?" Mousavi said. "Peace with any country would benefit our interests."

The Obama administration has said it wants to engage Iran, a different tactic than that of the Bush administration which sought to isolate the country. But Obama has also said that Iran''s nuclear and missile programs pose a threat.

The U.S. and its allies have charged Iran is trying to build nuclear weapons. Iran denies the charge, saying its nuclear program is designed for peaceful purposes such as power generation.

Mousavi said talks with the United States would be beneficial, as long as Iran does not have to "pay heavy costs such as the deprivation of advanced technologies," a reference to Iran''s disputed nuclear activities.

"We have to have the technology," Mousavi said, adding that the consequences of giving up the country''s nuclear program would be "irreparable" and that the Iranian people support the nuclear program.