Akbar Hashemi Rafsanjani, in his first interview since declaring his bid for an unprecedented third term as president, also said on Thursday that he would never abandon the country's nuclear programme, comparing such a step to ceding Iranian land.
"It is like giving away part of our territory," Rafsanjani said. "This is our nation's legitimate right ... especially when it is in accordance with international laws and regulations."
Rafsanjani, 70, served two terms as president from 1989 to 1997 and announced last week he would run in a 17 June election.
Opinion polls put him well ahead of other candidates.
Many Iran experts regard Rafsanjani as a pragmatic conservative with more power and influence to build bridges to the West than outgoing President Mohammad Khatami.
Rafsanjani said relations with the United States would be a major issue.
"There is no doubt that America is a superpower of the world and we cannot ignore them," Rafsanjani said at his office in a marble and mosaic palace used by the shah of Iran until the 1979 revolution.
"The Iranian government has pretty consistently refused to have any interest in wanting to have a responsible discourse"
US undersecretary of state for political affairs
The United States broke diplomatic ties with Iran in 1980 after the seizure of American hostages at the US embassy.
President George Bush in 2002 branded the country part of an "axis of evil" with North Korea and Saddam Hussein's Iraq.
Nicholas Burns, US undersecretary of state for political affairs, dismissed the likely value of direct engagement.
"We have not been, over the past 25 years, against communication. But the Iranian government has pretty consistently refused to have any interest in wanting to have a responsible discourse," he told the Senate Foreign Relations Committee in Washington.
US first step
Rafsanjani said his aim as president would be to turn the United States away from what he called adventurism in the Middle East but that the first move with Iran had to come from Washington.
"I think that Americans should gradually begin to adopt positive behaviour rather than doing evil. They should not expect an immediate reaction in return for their positive measures. It will take time.
Rafsanjani set up a deal with
Reagan to get American arms
"Over time, when Iranians witness America's positive measures, then they will feel that America has given up its hostile policies," Rafsanjani said.
Unblocking about $8 billion of Iranian assets frozen by the United States would be one way of showing Washington was serious, he added.
Asked why Tehran could not extend the olive branch, he said: "We have never pioneered enmities. When our people have this feeling of being oppressed by America, taking a positive step by the oppressed side would indicate that we are weak or might be considered as a display of fear."
Rafsanjani, seen in Iran as a consummate dealmaker, helped set up a secret deal with the administration of President Ronald Reagan in 1985 to obtain US weapons in return for help freeing Americans held hostage by Iranian-backed fighters in Lebanon.
He is also credited with a key role in ending a ruinous eight-year war with Iraq in 1988.
"I think that Americans should gradually begin to adopt positive behaviour rather than doing evil"
Akbar Hashemi Rafsanjani
The nuclear issue would be Rafsanjani's most immediate foreign concern if he became president, with Iran under pressure from the United States and Europe to abandon its plans to enrich uranium or face possible United Nations sanctions.
Rafsanjani said he would work to increase trust with the West and do his utmost to prevent the mounting nuclear crisis from turning into a military confrontation with Washington.
"One of my motivations to run was to use my familiarity with the international diplomatic atmosphere to solve this problem," Rafsanjani said.
"I believe the main solution is to gain the trust of Europe and America and to remove their concerns over the peaceful nature of our nuclear industry and to assure them that there will never be a diversion" to military use.
Since finishing his second term as president, Rafsanjani has headed the Expediency Council, a powerful arbitration body with legislative powers, and has influenced policy on everything from privatisation to the nuclear talks.
Rafsanjani is seen as one of the
most powerful figures in Iran
Most Iranians already see him as the most powerful figure in the country after Supreme Leader Ayat Allah Ali Khamenei.
Rafsanjani said he would work to offer more education, jobs and social opportunities for Iran's predominantly young population, which has grown disillusioned with strict clerical rule and disappointed at Khatami's failure to deliver reforms.
"We should live based on Islamic laws and not based on radical individuals' interpretations which sometimes make people's lives difficult," he said.