But an intensification of the Yemen conflict and certainly an escalation to direct conflict between Iran and Saudi Arabia could scare off foreign investors.

Iran basically believes in no other solution than a political one to the conflict in Yemen, he said. "The reality is that the Saudis and their allies have faced only the Yemeni people's resistance and experienced a disgraceful defeat".

Saudi Arabia has been leading an aerial bombing campaign in support of the government and against the Iranian-backed Houthi rebels.

The Islamic Republic, he said, wants Saudi Arabia to immediately join a peace process in Yemen and stop actions that have failed to bring peace to Yemen, but rather helped develop al-Qaeda and Daesh terror groups there.

"It is not the first time Saudi Arabia enters into correspondence against Iran in order to cover up its defeats in Yemen, and the global community is well aware of this fact", Khoshrou was quoted as saying by Iran's state TV.

Prime Minister Benjamin Netanyahu has called to "fix or nix" the deal, while U.S. President Donald Trump threatens to pull out of the agreement in May.

"These war-mongering and irresponsible remarks can be followed up legally at the worldwide level", said foreign ministry spokesman Bahram Ghasemi in a statement quoted by AFP.

The Houthis expelled pro-government forces from the capital Sanaa in September 2014 and went on to seize swathes of the impoverished Arabian Peninsula country.

The group further reported that drones used by the Houthi rebels to crash into Patriot missile batteries in Saudi Arabia share "near-identical design and construction characteristics" of Iranian drones.

Military escalation in response to the latest rocket salvo could mean more coalition air strikes - which have been widely criticised for killing civilians - or mobilising the Saudi National Guard from a mostly static position along the border to undertake a concerted ground assault inside northern Yemen.

The war has killed more than 10,000 Yemenis, mostly civilians, and displaced over 3 million, according to humanitarian agencies.

Several Western countries, the USA and the United Kingdom in particular, are accused of being complicit in the Saudi-led aggression on Yemen as they supply the Riyadh regime with advanced weapons and military equipment.