Iran's presidential candidate Mehdi Karroubi has said that relations between the United States and Iran are "vital," Iran's satellite channel Press TV reported on Monday.
Karroubi, a former Majlis (parliament) speaker who has officially announced his candidacy for next year's presidential election, made the remarks in his speech to university students in central Iranian city of Qom on Sunday.
In his speech, the reformist cleric said that Iranian officials had better "err on the side of caution," according to the Press TV report.
He advised Iranian officials to do their best to preserve the interests of the nation and avoid making statements that could play into the hands of hostile powers.
"Following the Islamic Revolution (in 1979), for some reasons, Tehran and Washington missed their chances several times to negotiate," Karroubi said.
The presidential candidate said he was ready to negotiate with any country but Israel should they recognize the legitimate rights of the Iranian nation.
Relations between Tehran and Washington must be restored, he added.
In October, Karroubi made similar remarks, saying that relations with the United States could be restored in a way that would preserve Iranian interests.
The announcement of his stance came amid speculation that the two old foes may seek rapprochement once U.S. President-elect Barack Obama takes office in January.
The United States broke off diplomatic relations with Iran on April 7, 1980 after a group of Iranian students seized the U.S. embassy in Tehran and captured some 60 U.S. diplomats in 1979, with 52 of them being in captivity for 444 days in the hostage crisis.
Karroubi contended the presidency in the country's 2005 presidential election, but was defeated in the first round.
Iran's upcoming presidential election will be held in June, 2009.