"The fact IS claimed responsibility proves that they [Saudi Arabia] were involved in the brutal attack".
Iran's supreme leader Ayatollah Ali Khamenei has accused the USA of creating Islamic State and fuelling instability in the Middle East. The US Department of State has warned that ISIS is turning into an increasing threat for Saudi Arabia and has the potential to destabilise the nation.
"We underscore that states that sponsor terrorism risk falling victim to the evil they promote", Trump said in a statement that also expressed condolences to the victims.
Earlier on Monday, Zarif met and held talks with the European Union (EU)'s foreign policy chief, Federica Mogherini, on a range of issues, including the 2015 multilateral nuclear deal with Iran.
Tehran also blamed Saudi Arabia for a terrorist attack in the city last week during which 17 people were killed.
"Qatar is a partner of the United Kingdom in the fight against terrorism but they urgently need to do more to address support for extremist groups, building on the steps they have already taken", Johnson said.
Iranian foreign minister Mohammad Javad Zarif said on Tuesday Saudi Arabia was supporting militants inside Iran, days after hardline Sunni group Islamic State claimed attacks in Tehran.
The pragmatist president championed a nuclear deal with the USA and five other powers in 2015 that led to the lifting of most sanctions against Iran, in return for curbs on its nuclear program.
Zarif also stressed that the United States could not affect Iran's relations with other countries.
On Tuesday, Iran's Foreign Minister Mohammad Javad Zarif referred to those remarks by the Saudi officials and called them a "direct threat and very unsafe provocation" by Riyadh.
Last month, the US Senate's Foreign Relations Committee voted in favor of legislation that would authorize Trump to impose new sanctions on Iran over its missile program, which Tehran has repeatedly said is defensive.
According to Iran's Press TV, at least 12 people have been killed in Wednesday's attacks while another 42 were injured and admitted to three hospitals for treatment. If U.S. rates rise, Saudi Arabia is seen likely to follow suit with its rates because the country's currency is pegged to the dollar.