Live updates: Follow the latest news on US-Iran war
The White House said on Wednesday that if Iran "fails to accept the reality of the current moment", the US will hit it harder than ever before.
It comes after Iran responded "negatively" to a reported US proposal aimed at ending the war. "Iran wanted to talk, President Trump is willing to listen," said White House press secretary Karoline Leavitt.
"As President Trump announced on Monday, the United States has been engaged over the last three days in productive conversations, which led the President to temporarily instruct the Department of War to postpone planned strikes against Iranian power plants and energy infrastructure."
Ms Leavitt added that reports circulating about a 15-point plan put forward by the US to end the conflict are not entirely factual.
Iran's Foreign Minister Abbas Araghchi later said Tehran is reviewing the US proposal but has no intention of holding talks.
The exchange of messages through mediators "does not mean negotiations with the US", he said on state television.
"They put forward ideas in their messages that were conveyed to top authorities, and if necessary, a position will be announced by them," Mr Araghchi said.
A senior Iranian official had earlier told Press TV that Tehran has insisted in its response to US overtures that "any cessation of hostilities will only occur on Tehran's own terms and timeline".
Reuters, quoting a senior Iranian source, said that Pakistan has delivered a US proposal to Iran, but the venue for any talks between Tehran and Washington to end the war has yet to be decided.
The source, who asked not to be identified due to the sensitivity of the matter, did not disclose details of the proposal and whether it was the 15-point US framework to end the war reported by news outlets. The source also said Turkey was helping to find ways to end the way and "either Turkey or Pakistan are under consideration as the venue for such talks".
Iran had played down reports about advanced talks to end the war, suggesting that Mr Trump is “negotiating with himself” but acknowledging willingness to engage.
Mr Trump claimed on Tuesday that Tehran “badly” wants to make a deal. His comments came as preparations were being made to send more US troops to the region, raising the prospect of a ground operation.
He said Vice President JD Vance and Secretary of State Marco Rubio are leading negotiations with Iran. He expressed optimism that a deal is in sight.
The Iranian military has a different view.
“Has the level of your inner struggle reached the stage of you negotiating with yourself?” the top spokesman for Iran's joint military command, Ebrahim Zolfaghari, said on Iranian state TV. “People like us can never get along with people like you.”
Mr Trump revealed to reporters an apparent trust-building effort with the Iranians. “They did something yesterday that was amazing actually,” he said. “They gave us a present and the present arrived today. It was a very big present worth a tremendous amount of money.”
He added that the Iranian “present” was “oil and gas-related” and connected to the “flow” in the Strait of Hormuz.
But Mr Zolfaghari insisted that “as we have always said … no one like us will make a deal with you. Not now. Not ever".
Iranian officials have told mediators over recent days that Tehran is ready to engage but on the condition that the talks include guarantees that it won't be attacked again, and that any ceasefire involves other fronts in the region, including Lebanon.
An Iranian source told CNN that Tehran is willing to listen to “sustainable” proposals to end the war. The US is believed to be pushing for in-person peace talks as soon as Thursday in Islamabad.
Amiri Moghadam, Iran's ambassador to Pakistan, told state media that "no direct or indirect negotiations have taken place between the two countries so far", but confirmed "an attempt to provide a basis for dialogue between Tehran and Washington, which we hope will be fruitful in ending this imposed war".
"Pakistan stands ready and honoured to be the host to facilitate meaningful and conclusive talks for a comprehensive settlement of the ongoing conflict," Pakistani Prime Minister Shehbaz Sharif wrote on X on Tuesday.
More reinforcements
According to Axios, Iranian officials told the countries trying to mediate peace talks – Pakistan, Egypt and Turkey – that they have now been tricked twice by Mr Trump and “we don't want to be fooled again”.
Earlier this week, Mr Trump announced a five-day postponement of threatened strikes on Iranian power plants. Iran responded with threats to attack power facilities in Israel and across the region.
Experts believe Mr Trump was probably trying to calm markets as the Strait of Hormuz blockade continues to drive up energy and other commodity prices ahead of Friday’s close, before the US resumes large-scale military operations.
About 1,000 soldiers with the Army’s 82nd Airborne Division are expected to be sent in the coming days to the Middle East, sources told CNN, adding to the growing military firepower in the region.
More reinforcements, including several fighter jet squadrons, are also expected to arrive in the coming days and weeks, according to Axios. A White House official said a ground operation remains an option but stressed Mr Trump has not yet made a decision.
Four weeks into a war that has killed thousands, created the worst energy shock in history and sparked global inflation fears, there was no let-up in air strikes from Iran and Israel on Wednesday.
The Israeli military said in a Telegram post that it had launched a wave of strikes against infrastructure across Tehran. It later said its air force had struck two naval cruise missile production sites in Tehran. The semi-official Iranian SNN News Agency said the strikes hit a residential area in the city, with rescuers searching the rubble.
Kuwait and Saudi Arabia said they had repelled fresh drone attacks. Drones attacked a fuel tank at Kuwait International Airport, causing a fire but no casualties, Kuwait's Civil Aviation Authority said.
Iran's Islamic Revolutionary Guard Corps said it had launched a new wave of attacks against locations in Israel, including Tel Aviv and Kiryat Shmona in the north, as well as US bases.
