The initial discussions in Islamabad with Saudi Arabia, Turkey and Egypt focused on proposals to reopen the Strait of Hormuz to shipping, sources familiar with the matter said. More talks will be held on Monday.
Iran's effective blockade of oil and gas shipments through the strait since the US and Israel began attacking the country on February 28 is spreading economic pain around the world.
Food and energy security and supply chains were among issues discussed in Pakistan, Egypt's foreign ministry said.
As the conflict entered its second month, Israel's military said it had launched over 140 air strikes on central and western Iran, including Tehran, over the 24 hours to Sunday evening, hitting ballistic missile launch sites and storage facilities, among other targets.
A chemical plant in southern Israel near the city of Beer Sheva was hit by a missile or missile debris as Israel fended off multiple salvos from Iran, prompting official warnings to the public to stay away due to "hazardous materials".
Another missile hit open ground near homes in Beer Sheva, located near several military bases, injuring 11 people.
The war has killed thousands of people and affected countries across the Middle East, with major aluminium plants in Bahrain and the United Arab Emirates damaged by air strikes over the weekend.
The UAE, which has faced more Iranian missile and drone attacks than any other country, is seeking reparations from Iran for attacks on civilians and vital facilities and clear guarantees to prevent any repetition, an adviser to the president said.
Pakistan has offered to host peace talks, but the United States, Israel and Iran have set out maximalist positions to end the warfare, complicating the path to a solution.
Iran's parliament speaker Mohammad Baqer Qalibaf accused the US of sending messages about possible negotiations while at the same time planning to send in troops, adding that Tehran was ready to respond if US soldiers were 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.
Yemen's Iran-aligned Houthis joined the conflict on Saturday launching their first attacks on Israel and raising the prospect they could target and thus block a second key shipping route, the Bab el-Mandeb Strait.
Analysts say renewed attacks there would pile further pressure on the world economy.
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 US military has said.
The Washington Post quoted US officials as saying the Pentagon was preparing for weeks of ground operations in Iran, adding that it was not yet clear if President Donald Trump would approve such plans.
Reuters has reported that the Pentagon has considered military options that could include ground forces.
Trump faces a stark choice between seeking a negotiated exit or escalating militarily that risks a protracted crisis, and would likely weigh further on his already low approval ratings.
"President Trump has poor options all around to end the war," said Jonathan Panikoff, former US deputy national intelligence officer for the Middle East.
"Part of the challenge is the lack of clarity related to what a satisfactory outcome would be," Panikoff added.
Washington said last week it had offered a 15-point ceasefire plan, with a proposal to reopen the Strait of Hormuz and restrict Iran's nuclear program, but Tehran has rejected the list and put forward proposals of its own.
An Israeli official said Israel would continue carrying out strikes against Iran on what were described as military targets, adding there was no intention to scale back the campaign ahead of any possible talks between Washington and Tehran.
With US midterm elections due in November, the increasingly unpopular war has weighed on Trump's Republican Party.
Demonstrators took to city streets across the US on Saturday in protests against the conflict.
Trump has threatened to hit power stations and other energy infrastructure if Iran does not open the Strait of Hormuz, though he has extended a deadline by 10 days to April 6.
Meanwhile, Prime Minister Benjamin Netanyahu flagged Israel will widen its invasion of southern Lebanon as it targets the Iranian-backed Hezbollah militant group.
