Iranian President Hassan Rohani said on Wednesday it was possible to turn more than three decades of enmity with the United States into friendship if both sides made an effort.
He was speaking in a Swiss television interview after arriving at the World Economic Forum in Davos where he will court the global business community and meet a series of oil company executives on Thursday.
Asked whether there could one day be a US embassy again in Tehran instead of the Swiss embassy representing US interests in Iran, the president told public RTS television: "No animosity lasts eternally, no friendship either lasts eternally. So we have to transform animosities into friendship."
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An interim deal with six major powers including the United States to restrict Iran's disputed nuclear program in exchange for a partial easing of economic sanctions entered into force this week.
Rohani travelled to Davos to persuade foreign investors to return to his country, which has some of the world's biggest oil and gas resources and a market of 76 million people.
In the interview, in which he spoke in Farsi voiced over into French, he said relations with Washington had been difficult in the past but with hard work and efforts by both sides, problems could be overcome.
"This effort is necessary to create confidence on both sides. Iran is in fact stretching out its hand in peace and friendship to all countries of the world and wants friendly, good relations with all countries in the world," the president said.
Skeptical on Syria He made no mention of the more difficult negotiations that lie ahead to conclude a permanent agreement on Iran's nuclear program, which the West believes is aimed at developing weapons.
However, he poured cold water on a UN-sponsored peace conference on the civil war in Syria, which opened in Montreux, Switzerland on Wednesday in the absence of Iran, a key ally of Damascus, which was excluded after refusing to endorse the goal of a transition from President Bashar Assad's rule.
"Reaching a conclusion will be very difficult but my wish is that if all efforts go in the direction of the wishes of the Syrian people, that is the direction that should prevail."
"As to whether this conference can achieve its objectives, I have a lot of doubt," he added. Rohani accused Saudi Arabia and Qatar of backing "terrorists" in Syria in an effort to extend their own influence in the Middle East.
Rohani will give a short speech on Thursday to chief executives from oil majors such as Eni, BP, Total and Shell, according to several executives who meet in Davos.
Heads of US companies such as Exxon Mobil could also attend, the executives said.
Tehran wants Western oil companies to revive its giant ageing oilfields and develop new oil and gas fields once sanctions are lifted and is improving its oil investment contract in order to lure them in.
The major OPEC producer has started implementing a nuclear deal with world powers, a step towards a broad settlement which could lead to the end of sanctions.
Western sanctions imposed over the nuclear program have choked Tehran's production – output is down a million barrels per day (bpd) since the start of 2012 to 2.7 million bpd – costing billions in lost revenue.
Top Iranian officials say the country can raise production to 4 million bpd within six months of sanctions being lifted. Western experts are more conservative, saying 3 million to 3.5 million bpd is more likely.
Encouraged by the preliminary nuclear deal struck between Iran and Western powers in November, Tehran and Big Oil have wasted no time making contact, in the hope of a full lifting of sanctions.
Paolo Scaroni of Italy's Eni was the first Western CEO to meet publicly with Iranian Oil Minister Bijan Zanganeh, on the sidelines of a meeting of the Organization of the Petroleum Exporting Countries last month.