Iran says it is ready to respond to a US ground attack, accusing Washington of preparing a land assault while seeking negotiations, as regional powers hold talks in Pakistan to try to end the fighting.
The foreign ministers of Pakistan, Saudi Arabia, Turkey and Egypt were set to meet in Islamabad on Sunday to discuss ways to halt the month-long US-Israeli war on Iran, which has killed thousands of people and disrupted global energy supplies.
Iran's parliament speaker Mohammad Baqer Qalibaf accused the US of sending messages about possible negotiations while secretly planning to send in ground forces, adding that Iran was ready to respond if US troops deployed.
"As long as the Americans seek Iran's surrender, our response is that we will never accept humiliation," he said in a message to the nation.
The war, launched on February 28 with US and Israeli strikes on Iran, has spread across the Middle East, with Yemen's Iran-aligned Houthis on Saturday launching their first attacks on Israel since the start of the conflict.
The strikes point to a potential new threat to global shipping, already hit by the effective closure of the Strait of Hormuz, a conduit for about one-fifth of global oil and liquefied natural gas supplies.
Washington has dispatched thousands of Marines to the Middle East, with the first of two contingents arriving on Friday aboard an amphibious assault ship.
The Pentagon was preparing for weeks of ground operations in Iran, possibly involving raids by Special Operations and conventional infantry troops, The Washington Post reported.
It was not known whether President Donald Trump would approve plans for deploying ground troops, the report said.
Secretary of State Marco Rubio has said the US was deploying forces to the region to give Trump "maximum" flexibility.
Pakistan, a potential mediator between Washington and Tehran, was hosting Sunday's talks a day after Prime Minister Shehbaz Sharif spoke to Iranian President Masoud Pezeshkian.
Pakistan's Foreign Minister Ishaq Dar held meetings with his Turkish and Egyptian counterparts in Islamabad on Sunday ahead of the four-way consultations.
Pakistan's army chief Asim Munir is also in regular contact with US Vice President JD Vance, a source familiar with the discussions said.
Separately, a Turkish source familiar with the matter said Ankara was working with other nations on a proposal to open the Strait of Hormuz.
The US said last week it had offered a 15-point ceasefire plan to Iran, with a proposal to reopen the waterway and restrict Iran's nuclear program, but Tehran rejected the list and put forward proposals of its own.
As efforts to find a negotiated end to the war inched forward, Israel's military continued its relentless air assault on Iran, saying on Sunday its forces had targeted Tehran's weapons manufacturing infrastructure.
Five people were killed in a strike on a pier in the southern port city of Bandar-e-Khamir that also destroyed two vessels, Iranian state media reported.
Israel also hit targets in Lebanon as part of its campaign against Iran-backed Hezbollah, killing three Lebanese journalists in a strike on a media vehicle, Lebanon's Al Manar TV reported, as well as a Lebanese soldier.
Israel's military said one of the journalists had been part of a Hezbollah intelligence unit and accused him of reporting on the locations of Israeli soldiers.
Early on Sunday, it said one of its soldiers had been killed during combat in Lebanon.
Israel struck a building housing Qatar's Al-Araby TV in Tehran on Sunday, the semi-official Mehr news agency reported.
Iran continued its attacks on Israel and several Gulf states.
Air defences shot down a drone near the residence of the leader of the Iraqi Kurdish ruling party in Erbil early on Sunday, security sources said.
Another drone strike targeted the home of the president of Iraq's Kurdistan region a day earlier.
With the Strait of Hormuz effectively closed, there is also concern about shipping lanes around the Arabian Peninsula and the Red Sea after Yemen's Houthis entered the fray.
They initially targeted Israel, but during the Gaza war they also hit ships in the Bab el-Mandeb Strait, a critical maritime choke point leading to the Suez Canal.