Iran has denied making a ceasefire "agreement" with Israel, just hours after US President Donald Trump said the two countries had agreed to put the fighting on hold.
Earlier today, in a social media post just after 6pm Washington time (8am AEST), Mr Trump said a ceasefire would begin in a matter of hours.
"It has been fully agreed by and between Israel and Iran that there will be a Complete and Total CEASEFIRE … for 12 hours, at which point the War will be considered, ENDED," he wrote.
About three hours after Mr Trump's announcement, Iran's Foreign Minister Abbas Araghchi said a final decision was yet to be made.
"As of now, there is NO 'agreement' on any ceasefire or cessation of military operations," he said in a post on social media.
Minutes later, Mr Araghchi followed up with another post that said Iran's military operations had "continued until the very last minute, at 4am".
"Together with all Iranians, I thank our brave Armed Forces who remain ready to defend our dear country until their last drop of blood, and who responded to any attack by the enemy until the very last minute," he said.
Israel has not yet publicly commented on the ceasefire announcement.
The Israel Defense Forces (IDF) has been contacted for comment.
Earlier, the Reuters news agency reported that a senior Iranian official confirmed Tehran had agreed to the US-proposed ceasefire.
Iran firing at US military bases was 'expected': Trump
Mr Trump's announcement came just hours after Iran fired a barrage of missiles at a US military base in Qatar, in retaliation for the US bombing three Iranian nuclear sites over the weekend.
Iran had notified Qatar of the attack on the Al Udeid base in advance, allowing time for its evacuation to prevent casualties.
Mr Trump subsequently thanked Iran in a social media post, and described the attack as "expected" and "very weak".
Iran and Israel have been trading missile fire since Israel attacked Iran on June 13, in what the Israel Defense Forces called a "pre-emptive, precise, combined offensive … on Iran's nuclear program". Israel's initial targets included military leaders and nuclear scientists.
A senior White House official told Reuters that Mr Trump had brokered the ceasefire deal in a call with Israeli Prime Minister Benjamin Netanyahu and Israel had agreed so long as Iran did not launch further attacks.
US Vice-President JD Vance said the war between Iran and Israel was effectively over, and it was time to "restart a real peace process" in the Middle East.
"We have to talk to Iran and, of course, to Israel about what the future holds because while we have obliterated the Iranian nuclear program, our hope and our expectation is that they're not going to try to rebuild that program," he told Fox News.
Asked about an earlier social media post in which Mr Trump raised the prospect of regime change in Iran, Mr Vance said: "I think what the president was saying … is if the Iranian people want to do something about their own leadership, that's up to the Iranian people."
Prime Minister Anthony Albanese said Australia welcomed the ceasefire announcement and had consistently called for "dialogue, diplomacy and de-escalation".
"The safety of Australians in the region is our priority," he said in a statement that was issued before Iran denied an "agreement" had been reached.
"We continue to closely monitor the situation in the Middle East and are deeply concerned about keeping Australians safe."