The Israeli military said on Monday that Iran launched multiple waves of missiles at Israel, and an attack had also been launched from Yemen for only the second time since the US-Israeli war began.
It said two drones from Yemen were intercepted early Monday but gave no further details. Yemen's Iran-backed Houthi militia entered the war on Saturday, firing missiles at Israel, escalating a conflict that has engulfed the Middle East.
Israel's military also said the Air Force was carrying out strikes on Tehran on Monday, targeting what it described as military infrastructure.
The latest attacks came a day after President Donald Trump said the US and Iran had been meeting "directly and indirectly" and that Iran's new leaders have been "very reasonable", as more US troops arrived in the region.
Pakistan, which is acting as an intermediary between Tehran and Washington, said it was preparing to host "meaningful talks" in the coming days aimed at ending the month-long Iran war. It was not clear whether the US and Iran had agreed to attend.
"I think we'll make a deal with them, I'm pretty sure, but it's possible we won't," Trump told reporters on Sunday evening as he traveled aboard Air Force One to Washington.
Trump said he thought the US had already accomplished regime change in Tehran after strikes killed the country's supreme leader and other top officials, but said twice that their replacements seemed "reasonable."
An initial Israeli strike on February 28 killed Iran's Supreme Leader Ali Khamenei, who was replaced by his son Mojtaba.
The war has spread across the Middle East, killing thousands, causing the biggest disruption ever to energy supplies and hitting the global economy.
Iran's parliament speaker, Mohammad Baqer Qalibaf, has accused the US of sending messages about possible negotiations while at the same time planning a ground invasion.
"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 US Department of Defense has dispatched thousands of troops to the Middle East, giving Trump the option of launching a ground offensive.
ISRAELI STRIKES
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.
Iranian state media reported strikes had hit Mehrabad airport and a petrochemical plant in the northern city of Tabriz.
Four weeks of intense US-Israeli bombardment has failed to silence Iran's missile and drone batteries, with Kuwait on Monday reporting it had intercepted five drones in areas under its protection.
A chemical plant in southern Israel near the city of Beersheba was hit by a missile or missile debris on Sunday as Israel fended off multiple salvos from Iran.
Iran also continues its effective blockade of the Strait of Hormuz, which carries 20% of global oil and gas shipments, spiking oil prices and spreading economic pain around the world.
Yemen's Iran-aligned Houthis joined the conflict on Saturday, launching their first attacks on Israel and raising the prospect they could target and block a second key shipping route, the Bab el-Mandeb Strait.
Stocks slumped in Asia on Monday as investors dug in for a protracted conflict, bringing a spike in inflation and the risk of recession to much of the globe. Japan's Nikkei index was down more than 3%.
Meanwhile, oil prices looked poised to extend their gains, with Brent headed for a record monthly rise. Brent crude futures jumped $2.43, or 2.16%, to $115 a barrel by 0342 GMT after settling 4.2% higher on Friday.
Global airlines have begun to hike fares and cut capacity to cope with the surge in the oil price, but analysts warn the industry's ability to remain profitable may depend on whether consumers pull back on flying as energy costs threaten household budgets.
MORE US TROOPS ARRIVE
Several hundred special operations personnel have arrived in the region, the New York Times reported on Sunday, citing two military officials. That comes on top of thousands of US Marines that came on Friday aboard an amphibious assault ship, the first of two contingents, the US military has said.
Reuters has reported that the Pentagon has been considering military options that could include ground forces, although Trump has not approved any of those plans, according to multiple news outlets.
In an interview with Financial Times published on Sunday, Trump said he wanted to "take the oil in Iran" and could seize the export hub of Kharg Island. Taking control of Kharg would require ground troops.
The island handles 90% of Iran's oil exports and seizing it would give the United States the ability to severely disrupt Iran's energy trade, placing enormous pressure on Tehran's economy.
The majority of Americans are opposed to the war and a military escalation, which would risk a protracted crisis, would likely weigh further on Trump's already low approval ratings ahead of November midterm elections for Congress.
Israeli Prime Minister Benjamin Netanyahu said on Sunday he had ordered the military to further expand its operations in southern Lebanon, citing continued rocket fire by Iran-backed Hezbollah.
Israel has said it will seize a chunk of southern Lebanon to create a "buffer zone" against Hezbollah, stoking fears among Lebanese of Israeli military occupation that could deepen instability and stoke further displacement.
