"If we achieve the deal's goals in cooperation with other members of the deal, it will remain in place", Rohani said, although he also warned that Iran was ready to resume nuclear activities curbed under the deal in exchange for sanctions relief if the USA withdrawal made it impossible for Iran's economy to continue benefiting.
In the run-up to the announcement, European leaders had lobbied for continuing the accord. He said there would be concern in the region about how the United States meant to address the threat if not through the deal.
Prime Minister Justin Trudeau has made a decision to ally himself with the likes of European leaders Emmanuel Macron and Angela Merkel over our allies the United States and Israel when it comes to the troubled Iran deal.
The deal came together after two years of intense discussions and aimed to restrict Iran's ability to develop nuclear weapons in exchange for lifting economic sanctions against Tehran.
The comments came as the United Nations nuclear watchdog confirmed that Iran is implementing "nuclear-related commitments" under its deal with world powers. It also agreed to reduce its stockpile of enriched uranium by 98% and limit uranium enrichment to 3.67%.
A number of countries have already cut reliance on Iranian oil, as well as other "traditional" sources of supply, due to a surge in cheaper USA crude exports.
Other world powers have vowed to uphold the landmark deal, which places restrictions on Iran's nuclear program and subjects it to global inspections.
"As of today, the IAEA can confirm that the nuclear-related commitments are being implemented by Iran", Amano stressed.
Iran and the U.S. have been enemies for decades.
Earlier, Iran's supreme leader Ayatollah Ali Khamenei chastised Mr Trump, while MPs set fire to a United States flag inside parliament, shouting, "Death to America!"
Jafari called for boosting Iran's defense capabilities following the US exit, saying the move proved that Washington is against Iran's defense and missile power and is using Iran's peaceful nuclear program just as an excuse.
Obama's deal did nothing to stabilize the region. When the pact was finally settled in 2015, it was widely celebrated as a major diplomatic achievement.
Despite US criticism that the accord does not go far enough in monitoring Iran's nuclear activities, the IAEA points to the fact that its inspectors have spent 3,000 man days per year on the ground in Iran. A renewal of sanctions would give the country's leaders little reason to adhere to their part of the deal. "In the years since the deal was reached, Iran's military budget has grown by nearly 40 percent, while its economy is doing very badly. If the regime continues its nuclear aspirations, it will have bigger problems than it has ever had before".
She said Mr Trump was "sending a message to North Korea" that any agreement they reach with the U.S. over its nuclear ambitions "will be worthless". "The Iran deal is defective at its core".
"With all of the places they're involved, it's bedlam and death and we can't allow that to happen".
Riyadh, which leads a regional coalition that intervened in Yemen's civil war to fight the Huthis, accuses Iran of supplying the militia with ballistic missiles. That's worth doing, because it would leave the door open to negotiating a new and better deal down the road.
Trump announced Tuesday that the USA would exit the accord aimed at curbing the Islamic Republic's nuclear program and reinstate financial sanctions on the country.