But Tehran argues that Washington has no right to reinstate such measures and is calling on the ICJ to order the US to "immediately suspend" them.

And a second round is set to come into effect in early November, this time blocking Iran's valuable oil and energy sales.

After unilaterally pulling out of a historic hard-won deal aimed at curbing Iran's nuclear programme in May, Trump slapped a first round of sanctions on the country in early August.

Tehran filed a suit against US President Donald Trump's decision to reimpose economic sanctions at the Hague-based International Court of Justice last month.

Iran's legal challenge against renewed sanctions by the United States goes before the UN's top court Monday, as Tehran seeks to avert painful punitive measures that could hurt its still fragile economy.

It is also demanding compensation.

The ICJ is expected to take a couple of months to decide whether to grant Tehran's request for a provisional ruling, while a final decision in the case could actually take years.

International sanctions against Iran were lifted in 2015 when it a struck a landmark accord with the US, Britain, China, France, Germany, Russia, agreeing to rein its nuclear ambitions.

'One-sided deal'

But Trump described it as a "horrible one-sided deal (that) failed to achieve the fundamental objective of blocking all paths to an Iranian nuclear bomb."

And even though all of the other parties pleaded with him not to abandon the pact, Trump pulled out and announced he would reinstate sanctions.

Tehran -- which argues that the move violates a little-known Treaty of Amity and Economic Relations signed by the two countries in 1955 -- says that the new sanctions are already hurting its economy. And its currency, the rial, has lost around half its value since April.

A raft of international companies -- including France's Total, Peugeot and Renault, and Germany's Siemens and Daimler -- have already suspended operations in Iran in the wake of the US move.

Iran says the sanctions are already hurting its economy and its currency, the rial, has lost around half its value since April (photo by: ATTA KENARE/AFP)

Washington "is besieging Iran economically, with all the dramatic consequence

s that a siege implies for the besieged population," Tehran said in court papers.

Iran "requests that, pending final judgement in the case, the Court indicate... that the USA shall immediately take all measures at its disposal to ensure the suspension of the implementation of all the May 8 sanctions," it said.

Eric De Brabandere, professor of international dispute settlement at Leiden University in the Netherlands, said that the support of many European states for the nuclear deal meant that "Iran's position is strengthened."

And the publicity generated by Iran filing a lawsuit at the ICJ could work in Iran's favour, the expert suggested.

"One of the objectives is to publicly denounce the acts of the United States," De Brabandere told AFP.

'Malign' activities

In his executive order, Trump argued that the sanctions would turn up the financial pressure on Tehran to come to a "comprehensive and lasting solution" regarding the activities that the international community regarded as "malign", such as its "ballistic missile programme and its support for terrorism."

" (photo by: Nicholas Kamm, HO/AFP/File)

But earlier this month, Iran's supreme leader Ayatollah Ali Khamenei appeared to rule out any immediate prospect of talks, saying "there will neither be war, nor negotiations," with the US.

Meanwhile, both the US and close ally Israel have called on European countries to do more to pressure Iran.

A separate 2016 complaint lodged by Iran against the US for freezing around $2 billion of its assets abroad is due to begin in October, when the United States will argue the ICJ has no authority to hear the case.