Correction, Mar. 19, 2018: An earlier version of this story stated President Trump could withdraw from the Iran nuclear deal in mid-April. The correct month is May.

The world will have to confront "another nuclear crisis" if the landmark 2015 agreement between Iran and world powers is scrapped, Iran's deputy foreign minister warned.

In a speech at London's Chatham House on Thursday, Abbas Araghchi said the "atmosphere of uncertainty" under US President Donald Trump has made it more difficult for Iran to stay with the deal, also known as the Joint Comprehensive Plan of Action (JCPOA).

"If we lose JCPOA, we would face another nuclear crisis, which would be very difficult to be resolved this time," he said.

"This is a choice between security and insecurity at the world level."

Araghchi, who served as Iran's top nuclear negotiator, also hinted that Iran could withdraw from the deal if the country fails to reap the expected benefits of the agreement.

"For Iran, we are supposed to benefit from the sanctions' lifting," he said. "If companies and banks are not working with Iran, we cannot remain in a deal that has no benefit for us."

Under the deal signed in Vienna between Iran and six world powers - the US, Russia, Germany, France, Britain and China, as well as the European Union - the leadership in Tehran scaled back the country's uranium enrichment programme.

According to UN inspectors, Iran continues to be in compliance with that condition.

In exchange of Iran scaling back its nuclear programme, sanctions on its economy were lifted, and Tehran was allowed to resume trading oil and gas on the international market. A total of $100bn in frozen Iranian assets was also released.

In his speech on Thursday, Araghchi noted that negotiators were able to resolve "a very complicated nuclear crisis" that could have turned into a "big and dangerous problem for the whole world".

US blacklist

Following the deal, Iran has gradually opened its country to foreign investment and welcomed more foreign visitors, injecting billions of dollars into its ailing economy.

However, there are several US sanctions that remain in place.

Analysts said that makes even non-American companies and investors who want to do business with Tehran wary of being penalised and blacklisted by Washington.

As a result, the economic gains Iran expected after it signed the deal have been stymied.

"Obviously such uncertainty has had a huge impact on foreign trade as investors remain wary and big banks have continued to stay away for fear of US sanctions," Mohammad Hashemi, a Tehran-based analyst, told Al Jazeera.

A wave of protests in recent months, widely blamed on the country's economic woes and years of political tension and alleged corruption, have added more pressure on the administration of reformist President Hassan Rouhani to do something about the economy.

Rouhani's administration had pinned its hope of economic revival on the nuclear deal. Conservatives, however, opposed the agreement saying the US is not a trustworthy partner.

"Now two years since the implementation of the deal it has become clear that those warnings have been true," said Hashemi.

'Anything but optimistic'

Hashemi said the current mood in Iran "is anything but optimistic", adding people are angry that despite Iran's "good faith" in complying with the deal, Trump's policies dashed those hopes "and highlighted US antagonism towards Iranians".

Since the 2016 US presidential campaign, Trump has repeatedly vowed to rip up the nuclear agreement with Iran, calling it the "worst deal ever" signed by the United States.

In January, President Donald Trump announced unless an agreement can be reached between the US, Europe and Iran to "fix" what he called the deal's "disastrous flaws", he will no longer issue waivers on US sanctions, and will withdraw from the agreement as early as mid-May.

Trump said Iran should curb its ballistic missile programme and allow inspections of its military facilities, demands that are not listed in the nuclear deal.

Iran rejected those conditions saying it would not "move beyond its commitments" to the existing agreement.

The other parties to the deal, particularly the Europeans, have insisted the deal is working, and Iran has kept its part of the bargain.

Boris Johnson, the UK's foreign secretary, also said no country has come up with a "better idea" to replace the agreement.