Trump did not provide additional details on the move which he announced on Twitter on Wednesday.
“I have just instructed the Secretary of the Treasury to substantially increase Sanctions on the country of Iran!” Trump tweeted, Presstv Reported.
Trump or the White House did not provide clarification on whether the sanctions announcement came in response to the attacks on two Saudi Aramco oil facilities on Saturday that knocked out more than half the kingdom’s production.
Yemen's Houthi fighters have claimed responsibility for the attack on the Saudi oil facilities, but the United States has rejected the claim with Trump saying that Iran appears to be responsible for the strike.
US Vice President Mike Pence also said on Tuesday that it “looks like” Iran was responsible for the attack, but added US intelligence agencies were working to confirm the details.
US Defense Secretary Mark Esper has said the American military was preparing a response to the attacks.
Esper briefed Trump in the White House on Monday. He did not directly put blame on Iran for the attack but accused it of undermining international order.
US Secretary of State Mike Pompeo put the blame for the operation on Iran, claiming, “Tehran is behind nearly 100 attacks on Saudi Arabia” and that “there is no evidence the attacks came from Yemen.”
Tehran, however, dismissed the allegation, saying Washington seems to be shifting from a failed campaign of “maximum pressure” to one of “maximum lying” and “deceit” against the Islamic Republic.
Iranian Foreign Minister Mohammad Javad Zarif said in a tweet that “US & its clients are stuck in Yemen because of illusion that weapon superiority will lead to military victory.”
Yemen said it used 10 drones for Saturday’s operation, which was one of their largest retaliatory attacks ever inside the kingdom.
The Yemeni army has said the raids were carried out on the back of an intelligence operation and in cooperation with “certain honorable and freedom-seeking individuals within Saudi Arabia.”
‘US aggression be met with counteraction’
Iran has warned the United States that any action taken against the country over the false accusation that Tehran was behind the attacks on Saudi Arabian oil facilities will be met with an immediate response.
In an official note passed to the Swiss Embassy in Tehran, which represents American interests, Iran reiterated that it was not behind the Saturday attacks on Saudi Arabian oil facilities.
It condemned and rejected claims by Trump and Pompeo that Iran had been involved.
“If any action takes place against Iran, the action will be faced by Iran’s answer immediately,” the note said.
Meanwhile, Iranian President Hassan Rouhani has described American claims as slanderous and simply part of Washington’s continuing campaign to put pressure on Iran.
“While exerting psychological and economic pressure on the Iranian people [through sanctions], they want to impose maximum… pressure on Iran through slander,” Rouhani said of the Trump administration. “Meanwhile, no one believes these accusations.”