US gold futures jumped 1.6% to $1,440.20 an ounce
A senior U.S. State Department official said the United States is building a coalition with its allies to protect Gulf shipping lanes by having "eyes on all shipping" following recent attacks on oil tankers that Washington blamed on Iran.
Trump told reporters he was signing an executive order for the sanctions amid tensions between the United States and Iran that have grown since May, when Washington ordered all countries to halt imports of Iranian oil.
Trump told reporters the sanctions, which will target Iranian Supreme Leader Ayatollah Ali Khamenei, were in response to Tehran's downing of a US drone last week.
The tensions between the US and Iran come after Iran shot down a US military drone last week.
After the drone's downing, Trump secretly authorised US Cyber Command to carry out a retaliatory cyber attack on Iran, The Washington Post reported.
Consequently, major airlines around the world have already rerouted their aircraft.
On June 20 , an Iranian missile destroyed a US Global Hawk surveillance drone.
Oil futures rallied on fears of disruption to flows in the Middle East, which provides more than a fifth of the world's oil output.
Moscow has backed Tehran in its stand off with the United States since Washington pulled out of an international 2015 nuclear agreement with Iran last year.
Iran's Revolutionary Guard said it had shot down a US :spy drone" over its territory.
Ryabkov told reporters that Moscow had repeatedly warned Washington and its regional allies about what he called the 'unthinking and reckless pumping up of tensions in an explosive region.'
Attacks on two oil tankers on June 13, which the US also blamed on Iran, have raised fears of broader confrontation in the region.
Hunt called on Iran to "cease all forms of destabilising activity" and said Britain was working with other countries to try to find a diplomatic solution to the escalating standoff between Tehran and Washington.
'We want to get them back to the table,' Trump told Fox News in an interview. 'I'm ready when they are,' adding that he was in 'no rush.'
Washington said the move aimed to dry up revenues to the elite Iranian military force but analysts called it largely symbolic.
US President Donald Trump last month refused to give waivers to countries like India from buying oil from Iran, in an attempt to reduce Iran's oil exports to zero
US President Trump last month refused to give waivers to countries like India from buying oil from Iran, in an attempt to reduce Iran's oil exports to zero.
US President Donald Trump said a deal with Iran on its nuclear programme was possible.
Rouhani's remarks could also be seen as a defense of his stance following the rare public chastising by the supreme leader.
The US reimposed sanctions on Iran in November after pulling out of a 2015 nuclear accord between Tehran and six world powers.
Zarif and the current Secretary of State, Mike Pompeo, have never spoken directly, according to Iran's mission at the United Nations. They instead tend to communicate through name-calling on Twitter or through the media.
The prospect of war was now the main topic of conversation in workplaces, taxis and buses, Nima Abdollahzade, a legal consultant at an Iranian startup company, told Reuters.
Oil analysts indicate the possibility of supply disruptions on top of an already tight crude market sending oil prices ‘violently upward’. Some are even predicting another oil shock.
The Trump administration last week ordered non-essential diplomatic staff out of Iraq, citing threats from Iranian-backed Iraqi armed groups.