Donald Trump has vowed to implement more stringent economic measures against Iran and any nation that supports or trades with it.
The US president declared on Truth Social, in all capital letters, that he was initiating "the most crushing economic operation ever taken against any country," without specifying further details or naming any countries besides Iran.
This announcement follows the formal expiration of a 60-day ceasefire on Monday, with no diplomatic resolution in sight for the conflict that the US and Israel commenced in late February. Tehran has stated that Trump's threat would only escalate animosity.
If enacted, these measures would intensify the economic pressure campaign on Iran, intended to force its capitulation.
In April, the US imposed a series of sanctions on foreign banks and companies conducting business with Iran, after it became evident that military action had not resulted in the overthrow or surrender of the regime in Tehran, as Trump had initially anticipated.
Conversely, since the war began, Iran has managed to disrupt maritime traffic through the Strait of Hormuz, leading to a global increase in energy prices.
With the US midterm elections approaching in November, Trump is facing scrutiny regarding the financial burden of the war on American consumers.
On Wednesday evening, the US president stated that he was launching "economic D-Day" on Iran due to its failure to reach an agreement with the US.
"ANY country that allows its financial institutions, businesses, airports, or government entities to provide any type of lifeline to Iran will itself face TREMENDOUS Economic Consequences," Trump asserted.
He did not specify the penalties that countries might incur.
Trump continued: "Oil smuggling, swap lines, cash transfers, exchange houses, ship registries, front companies - it all needs to stop NOW. You know who you are."
This comes a day after the United Arab Emirates (UAE), a US ally, announced it would be severing all financial and economic ties with Iran, following a new missile threat from the country.
The UAE's defence ministry reported detecting two ballistic missiles launched from Iran targeting maritime traffic, both of which landed in the sea.
Iranian entities have historically utilized Dubai's financial system for money transfers via exchange houses and shell companies.
Following the UAE's decision, Iran's armed forces cautioned neighboring Gulf states against providing support to the US military, stating that any assistance would be considered collusion.
Although China was not explicitly named in the post, its businesses are the largest purchasers of oil from Iran, a crucial source of funding for Tehran.
Since the war's inception, Washington has sanctioned several so-called teapot refineries – privately owned oil processing plants, predominantly located in Shandong province, eastern China.
At the time, China's Ministry of Commerce declared the sanctions "in violation of international law and the basic norms governing international relations" and mandated that the sanctions "shall not be recognised, enforced or complied with."
Iran's Foreign Minister Abbas Araghchi described Trump's latest post as "a diversion" from America's own economic challenges.
"Doubling down on failed policies will only bring further defeat - and enmity of Iranians," he wrote on X.
Operation Economic Fury, announced by the US Treasury Department and the Pentagon in April, aimed to weaken Tehran's warfighting capabilities by cutting off its revenue streams, and also included a naval blockade to halt Iranian exports.
US Treasury Secretary Scott Bessent stated last week that the US would soon impose economic isolation on Iran "like the world has never seen before."
Trump also recently reportedly threatened to bomb Oman – a US ally – if it "gets in the way" of his administration's negotiations with Iran.
The US and Oman have been engaged in separate negotiations with Tehran to reopen the Strait of Hormuz, a critical trade route through which approximately 20% of the world's crude oil and liquefied natural gas typically flows.
The BBC has reached out to the Chinese embassy in Washington, the White House, and the US Treasury Department for comment.
