The four-week war has spread across the Middle East, killing thousands of people and hitting the global economy with soaring energy prices.
The United States and Israel launched strikes on Iran on February 28 during talks with Tehran about its nuclear program that had not yet yielded a deal.
On Thursday, Trump threatened during a cabinet meeting at the White House to increase pressure on Iran if it did not make a deal.
He later posted on social media that he would pause threatened attacks on Iranian energy plants for 10 days until April 6 at 8pm (11am AEST on April 7).
"Talks are ongoing and, despite erroneous statements to the contrary by the Fake News Media, and others, they are going very well," he said in his Truth Social post.
Iran has said it is not engaged in talks with Washington and Trump has not identified who the US is negotiating with in Iran, with many high-ranking officials killed in the war.
On March 23, Trump announced a halt to all threatened strikes against power plants and energy infrastructure for a five-day period, but has extended it to 10 days.
There was no immediate reaction from Tehran, but the Wall Street Journal cited peace talk mediators as saying Iran did not ask for a 10-day pause on such strikes.
Iran has said it would return strikes on energy facilities in the Gulf region if Trump follows through with his threat.
Iran has effectively blocked the Strait of Hormuz, which carries about 20 per cent of global oil and liquefied natural gas, spiking energy prices and roiling financial markets.
The prospect of tit-for-tat strikes on civilian infrastructure could further rattle global markets and threaten the livelihoods of millions of civilians in the region who rely on electricity to power their cities and supply fresh water.
Iranian media reported strikes on residential areas in Tehran, Qom, Urumia early on Friday morning, with at least six people killed in Qom and several people killed and injured in Urumia.
Israeli military said on Friday it struck ballistic missile production sites and air defence systems across Iran overnight, including targets in Tehran and western regions, in operations that the Israeli military says it is aimed at degrading Iran's missile capabilities and reducing threats to Israel.
The war has massively disrupted shipping, sending crude oil prices up around 40 per cent, seen liquefied natural gas prices spike, and prices for nitrogen-based fertilisers, critical to food production, rise about 50 per cent.
An Iranian official told Reuters that a 15-point US proposal, conveyed to Tehran by Pakistan, was reviewed in detail on Wednesday by senior Iranian officials and the representative of Iran's supreme leader, who felt it served only US and Israeli interests.
However, diplomacy had not ended, the official said.
The proposal included demands ranging from dismantling Iran's nuclear program to curbing its missiles and effectively handing over control of the Strait of Hormuz, according to sources and reports.
Despite Trump's upbeat assessment, Iran continued to retaliate against US and Israeli strikes by hitting Israel and US bases.
It also struck Gulf states and effectively blocked Middle East fuel exports via the Strait of Hormuz, which carries about 20 per cent of global oil and liquefied natural gas.
Trump suggested on Thursday that Iran let 10 oil tankers transit the strait as a goodwill gesture in negotiations, including some Pakistan-flagged vessels.
The Pentagon was looking at sending up to 10,000 additional ground troops to the Middle East, the Wall Street Journal reported on Thursday.
