A spokesman for Iran's Foreign Ministry said Tuesday that new U.S. sanctions against Iran mark a permanent end to a diplomatic path for resolving tensions between the two countries.
"Imposing fruitless sanctions on Iran's leadership and the chief of Iranian diplomacy mean the permanent closure of the road of diplomacy with the frustrated U.S. administration," Abbas Mousavi wrote on Twitter.
He added that U.S. President Donald Trump's approach is "destroying the established international mechanisms for maintaining world peace and security."
The comments follow Trump's move to impose what he called "hard-hitting" new financial sanctions against Iranian Supreme Leader Ayatollah Ali Khamenei and eight senior commanders in the Iranian military and the Islamic Revolutionary Guards Corps.
Trump signed an executive order Monday he said would curb access that Khamenei and Iran would have to world financial markets. Treasury Secretary Steven Mnuchin said the action would "literally" lock up "tens and tens of billions of dollars" of Iranian assets.
Mnuchin also said the United States could also target Iranian Foreign Minister Mohammad Javad Zarif, one of Tehran's best known figures on the world stage, with sanctions in the coming days.
Trump called his order a "strong and proportionate" American response to Tehran's shoot-down last week of an unmanned U.S. drone, which Washington says occurred in international airspace near the Strait of Hormuz and Iran claims occurred over its airspace.
The U.S. leader said he imposed the sanctions because of a series of "belligerent acts" carried out by Iran, which U.S. officials say include Iran's targeting of Norwegian and Japanese ships traversing the Strait of Hormuz with mine explosions days before the attack on the drone.
The executive order is aimed at pushing Tehran back to one-on-one talks with the U.S. over its nuclear weapons program after Trump last year withdrew from the 2015 international pact restraining Iran's nuclear program in exchange for sanctions relief. Trump called the international deal negotiated by his predecessor, former President Barack Obama, "a disaster."
"We'd love to be able to negotiate a deal," Trump said.
But he declared, "Never can Iran have a nuclear weapon," adding, "They sponsor terrorism like no one's seen before."
He said, "I look forward to the day when sanctions can be lifted and Iran can be a peace-loving nation. The people of Iran are great people."
Mnuchin said earlier sanctions imposed when Trump pulled out of the international agreement have been "highly effective in locking up the Iranian economy."
He said some of the sanctions Trump imposed Monday had been "in the works" before the drone was shot down, and some were being imposed because of the attack on the drone.
The Treasury Department headed by Mnuchin said that any foreign financial institution that engages in a "significant financial transaction" with the Iranians targeted by the sanctions could be cut off from U.S. financial deals.
Secretary of State Mike Pompeo described the new sanctions as "significant" as he left Washington on Sunday for a trip to Saudi Arabia and the United Arab Emirates to continue the Trump administration's effort to build a coalition of allies to counter Iran. Pompeo met Monday with Saudi King Salman and Crown Prince Mohammed bin Salman.
"The world should know," Pompeo said, "that we will continue to make sure it's understood that this effort that we've engaged in to deny Iran the resources to foment terror, to build out their nuclear weapon system, to build out their missile program, we are going to deny them the resources they need to do that thereby keeping American interests and American people safe all around the world."
Iran has defended its missile work as legal and necessary for its defense. Tehran has sought support from the remaining signatories to the 2015 agreement to provide the economic relief it wants, especially with its key oil exports as the U.S. has tightened sanctions in an attempt to cut off Iranian oil shipments.