After re-imposing sanctions, the U.S. had declared IRGC as a terrorist organisation and indicated that there was a credible Iranian threat that warranted diverting USA warships to the Gulf.
Later, Zarif told reporters there was "no possibility" of negotiations with the United States to reduce spiralling tensions, describing U.S. pressure as an "act of suicide".
Iran's foreign minister has said "extremist individuals" in the US government were pursuing risky policies and Tehran is not seeking confrontation. In other comments carried on the semi-official Mehr news agency, Zarif was quoted as saying "a multilateral deal can not be treated unilaterally".
It is uncertain whether the strikes on Yemen are considered sufficient punishment of Iran through their Houthi proxies (Saudi Foreign Minister Adel al-Jubeir dubbed the Houthis on Thursday "an indivisible part of Iran's Revolutionary Guard Corps" on Twitter), or whether these events, and such opinion pieces, are meant to draw in American military power.
Vice Minister of Defence Khalid bin Salman said the Houthi attacks against Aramco's facilities proved the rebel the group was an "Iranian tool" which Tehran used to implement its agenda in the strife-torn region. Tehran also denies providing arms to the Houthis. Fawaz Ahmed told The Associated Press he saw three bodies being retrieved from the rubble - a father, mother and child, all buried together. At least 40 other people were wounded, according to Yemen's health ministry.
The residents say the airstrikes started early on Thursday, with coalition jets bombing military sites belonging to the rebel Houthis who have been at war with the coalition since 2015.
Donald Trump dismissed claims that the U.S. was spoiling for a war, and said on Twitter that Iran would be willing to negotiate "soon". In response, Iran's supreme leader issued a veiled threat Tuesday, saying it wouldn't be hard for the Islamic Republic to enrich uranium to weapons-grade levels.
"We will actually with our partners also be deliberate in considering our response, what to do about it, how to deal with it", he said, adding the United States and France were helping with the probe.
The US State Department has ordered all nonessential government staff to leave its embassy and consulate in Iraq.
The movement of diplomatic personnel is often done in times of conflict, but what is driving the decisions from the White House remains unclear. The U.S. Consulate in Basra has been closed since September following a rocket attack blamed on Iranian-backed militias. The U.S. military's Central Command said without elaborating that its troops were on high alert.
A spokesman for the Iranian Mission to the United Nations insisted Thursday that Tehran poses no threat and has no intention of attacking U.S. assets.
A senior British officer in the US -backed coalition fighting the Islamic State group appeared to push back against the USA claims, telling reporters earlier in the week that there'd been no increased threat from Iranian-backed forces in Iraq and Syria. Maj. Gen. Chris Ghika's comments exposed global skepticism over the American military buildup.
Iran recently threatened it might resume higher enrichment by July 7, beyond the level permitted by the current deal between Tehran and world powers.
Oil climbed for a third day, with Brent rising 1.4% to $72.8 in London, as Middle East tensions and falling USA gasoline stockpiles kept investors on edge.
Though Iran maintains its nuclear program is for peaceful purposes, scientists say the time needed to reach the 90 percent threshold for weapons-grade uranium is halved once uranium is enriched to around 20%.
Minister of State for Foreign Affairs Anwar Gargash said he would not speculate about who was behind Sunday's sabotage acts on four vessels, including two Saudi tankers, near Fujairah emirate while an investigation was under way and due to be completed within days. He declined to blame Iran directly, although he repeatedly criticised Tehran. Absent a dialogue between Iran and the United States and Iran and the UAE-Saudi Arabia, however, the atmosphere is likely to remain one of confusion and anxiety, in which rhetoric about ramping up conflict could spur further attacks and uncertainty. It did not elaborate.
Meanwhile, the Qatar-funded satellite news broadcaster Al-Jazeera said Qatar is trying to "defuse escalating tensions".