UNITED NATIONSinfo-icon: USinfo-icon President Donald Trumpinfo-icon and his Iranian counterpart Hassan Rouhani clashed sharply at the UN General Assembly on Tuesday, with the former urging the international community to isolate Tehraninfo-icon from global trade, and the latter calling US sanctions "economic terrorism".

Weeks of speculation about a possible breakthrough meeting devolved into a warinfo-icon of words over Trump's decision to withdraw from the 2015 nuclear deal and to reimpose economic sanctions on Iraninfo-icon.

Trump fired the first volley, repeating his administration's contention that Iran is the worldinfo-icon's "leading sponsor of terrorism".

"Iran's neighbours have paid a heavy toll for the regime's agenda of aggression and expansion," Trump said, accusing Iranian leaders of having "embezzled billions of dollars" from the country's treasury to wage proxy wars.

"We ask all nations to isolate Iran's regime as long as its aggression continues."

Trump promised Iran would face more economic difficulties when the second round of sanctions targeting the energy sector snap back on November 5.

Rouhani later hit back at Trump saying his decision to impose more sanctions is a form of "economic terrorism", accusing the US administration of trying to topple his government.

"It is ironic that the US government does not even conceal its plan for overthrowing the same government it invites to talks," Rouhani said.

'Weakness of intellect'

Without directly naming Trump, he said some world leaders are undermining world security by their "recklessness and disregard of international values and institutions".

"Confronting multilateralism is not a sign of strength, rather a symptom of the weakness of intellect," he said.

Shunning multilateralism signals an "inability in understanding a complex and interconnected world", Rouhani said.

"The government of the US - at least the current administration - seems determined to render all international institutions ineffectual," he said.

"Unilateral and illegitimate" sanctions imposed by the United Statesinfo-icon against the Islamic Republic are tantamount to "economic terrorism" and are in violation of world nations' right to progress.

"Unlawful unilateral sanctions in themselves constitute a form of economic terrorism and a breach of the 'Right to Development.'

The economic war that the United States has initiated under the rubric of new sanctions not only targets the Iranian people but also entails harmful repercussions for the people of other countries, and that war has caused a disruption in the state of global trade," Rouhani said in his address.

He added, "The Iranian people have demonstrated their unwavering resilience during the past forty years despite the difficulties and constraints caused by sanctions, and have shown that they can overcome this difficult phase as well. The multi-millennial historyinfo-icon of our country demonstrates that Iran and Iranians have never broken in the face of a storm of events--not even been bowed."

The Iranian president stated that Washington's approach of resisting the wishes of the Iranian people is doomed to failure.

"The policy of engagement and cooperation with Iran has produced positive outcomes for other nations, as best reflected in Iran's cooperation with friendly countries in the fight against terrorism. 

"The US understanding of international relations is authoritarian. In its estimation, might makes right. Its understanding of power, not of legal and legitimate authority, is reflected in bullying and imposition. No state and nation can be brought to the negotiating table by force, and if so, what follows is the accumulation in the 'grapes of wrath' of those nations, to be reaped later by the oppressors," Rouhani pointed out.

"This illusion should be cast away, once and for all, that one can aspire to securing more peace and security at the cost of denying others' peace and security. Negligence or ineffectiveness of international institutions can endanger world peace. Those seeking dominance and hegemony are enemies of peace and the perpetrators of war," the Iranian president said.

He underlined that the incumbent US administration seems determined to render all international institutions unproductive.

In May, the Trump administration pulled out of the historic 2015 deal designed to prevent Iran from building a nuclear bomb. In August, the first round of US sanctions were reimposed on Iran.

There was speculation whether the two leaders would meet in New York City, after Trump said he would be willing to meet without preconditions.

But Rouhani said in interviews Iran would not be willing to hold talks with the United States, until it decides to return to the 2015 nuclear deal, also known as the Joint Comprehensive Plan of Action (JCPOA). 

The five remaining parties to JCPOA - Franceinfo-icon, Britaininfo-icon, Germanyinfo-icon, Chinainfo-icon and Russiainfo-icon - agreed during a meeting in New York late on Monday to set up a payment system to preserve businessinfo-icon ties with Iran despite US sanctions.

The Iranian leader said he was pleased the international community did not follow the Trump administration's "unilateral and illegal withdrawal from the JCPOA".