Obama says world should carry out its end of Iran nuclear deal

US President Barack Obama has said that world powers should carry out their end of the Iran nuclear deal and allow companies to do business in the Islamic republic.

"So long as Iran is carrying out its end of the bargain, we think it is important for the world community to carry out our end of the bargain," he said on Friday after a nuclear security summit with other world leaders.

This year, the international community lifted a raft of sanctions on Iran in exchange for the country curbing its controversial nuclear program.

But this month, Iran's Supreme Leader Ayatollah Ali Khamenei accused Washington of failing to respect the terms of the agreement.

Meanwhile, international businesses have been cautious about returning to do business in Iran, fearing that they could fall afoul of continuing US sanctions aimed at Tehran's other non-nuclear policies.

"What I would say is also important is Iran's own behaviour in generating confidence that Iran is a safe place to do business," Obama said.

The US president said Treasury Secretary Jacob Lew and his counterparts within the P5+1 nations that negotiated the deal with Iran would be "providing clarity to businesses about what transactions are in fact allowed".

"And it is going to take time over the next several months for companies and their legal department to feel confident... there may not be risks of liability if they do business with Iran," Obama said, adding, "But the spirit of the agreement involves Iran also sending signals to the world community of businesses that it is not going to be engaging in a range of provocative action that might scare business off." 

"When they launch ballistic missiles with slogans calling for the destruction of Israel, that makes businesses nervous," he said. 

The limited polls that are conducted in Iran show scepticism about the country's economic situation following decades of sanctions.

A host of non-nuclear sanctions related to terrorism sponsorship, ballistic missile programs and a crackdown on demonstrators remain in place.

According to a CISSM and IranPoll.com survey released on Thursday, Iranians have a less favourable impression of the country's economic situation now than they did before the deal came into effect in January.

While a majority of those polled back deeper economic engagement with the West, almost 70% do not believe the United States will meet its promises under the agreement.

Officials say that even with sanctions lifted, US and other non-Iranian companies have been reluctant to do business with Iran for fear of getting tangled in a thicket of US regulations.