After Donald Trump's re-election, Iran has projected indifference, officially stating it expects no fundamental shift in US policy, especially on sanctions or the Middle East's wars.
However, Trump is set to return to the White House in January - after defeating US Vice President Kamala Harris in Tuesday's election - at a delicate time for Tehran whose allies in the region have suffered severe blows in conflicts with Israel.
Trump's victory came with the Middle East in turmoil after the outbreak of Israel's brutal offensive on Gaza, which began in October 2023.
That war has now spread to Lebanon, where Israel says it is fighting Hezbollah, an ally of Iran which itself has now twice launched retaliatory attacks on Israel, in April and October, using drones and missiles.
"Iran traditionally takes a 'wait and see' approach following the election of a new American president," said John Ghazvinian, who authored a book on US-Iran history.
He says the method of Iran's supreme leader Ayatollah Ali Khamenei, who has the final say in all state matters, is to observe "what concrete actions the new administration takes (or doesn't take) as an indication of its approach to Iran."
During his first term from 2017, Trump pursued a "maximum pressure" strategy of punishing sanctions on Iran, driving tensions between the long-time adversaries to new heights.
In December 2017 he recognised Jerusalem as Israel's capital and the following year moved the American embassy there. Trump also recognised Israeli sovereignty over the Golan Heights, which Israel captured from Syria in 1967 and later annexed.
"Trump has already crossed the red line that existed in the relations between Iran and the United States, as well as in the region itself," said foreign policy analyst Rahman Ghahremanpour.
Given the current tensions around the region and his history of foreign policy, the risk he poses "is greater for Iran's interest" compared to Democrats, he added.
Iranian President Masoud Pezeshkian on Thursday said "It makes no difference to us who won the US election."
Quoted by the official IRNA news agency, Pezeshkian added that Iran has prioritised "developing relations with Islamic and neighbouring countries."
Iran also called Trump's victory an opportunity for the US to reassess past "wrong policies".
Foreign ministry spokesman Esmaeil Baghaei, also quoted by IRNA, said his country has "very bitter experiences with the policies and approaches of different US governments in the past."
In 2018, Trump unilaterally withdrew the United States from the 2015 nuclear deal between Iran and world powers and reimposed harsh sanctions on the Islamic Republic.
Under his presidency in 2020, the United States killed Islamic Revolutionary Guard Corps General Qasem Soleimani in an air strike on Baghdad airport.
On Tuesday, Trump told reporters he was "not looking to do damage to Iran".
"My terms are very easy. They can't have a nuclear weapon. I'd like them to be a very successful country," he said after he cast his ballot.
Iran has always denied any ambition to develop a nuclear weapons capability, insisting its activities are entirely peaceful.
But it gradually suspended its compliance with caps on nuclear activities after the US pullout from the nuclear deal in 2018.
Pezeshkian, who took office in Iran in July, favoured reviving that agreement and called for ending his country's isolation.
Last month, Foreign Minister Abbas Araghchi said indirect nuclear talks with the United States, via Oman, had stopped because of regional tensions.
Ghazvinian said that "ending Iran's isolation will simply not be an agenda" for Trump.
"A Trump administration is likely to pursue provocative, escalatory moves aimed at crushing or collapsing the Islamic Republic," he said.