The US is prepared for its military campaign against Iran to last four to five weeks, but "we have capability to go far longer than that", President Donald Trump said on Monday.
Trump, who made the remarks at the White House, claims his decision to attack Iran was justified because Tehran's missile and nuclear programs posed an imminent threat to the US and its allies in the region. He has also described his attack as retribution for Iranian actions against the US since the establishment of the Islamic Republic in 1979.
Iran has retaliated against the US-Israeli attacks primarily by targeting ships, port infrastructure, airports and energy installations in the Mideast Gulf, in addition to US military bases. Iran's retaliatory attacks against its neighbors came as a surprise, Trump said in a separate interview with CNN on Monday.
The Joint Maritime Information Center has raised the threat level in the strait of Hormuz to "critical" in the wake of several attacks on commercial vessels. Additional war risk premium rates in the Mideast Gulf have surged to around 1pc of hull and machinery value.
State-owned QatarEnergy has halted production of LNG and associated products following drone attacks on operating facilities in Ras Laffan and Mesaieed Industrial City. The US-flagged tanker Stena Imperative, berthed in the Port of Bahrain, caught fire on Monday after being hit by two unknown projectiles.
State-controlled Saudi Aramco has shut its 550,000 b/d Ras Tanura refinery on Saudi Arabia's east coast after it was struck by debris from intercepted Iranian drones early on Monday.
Trump argued that Iran's attacks on Mideast Gulf Arab states prompted its leaders to offer military support for the joint US-Israeli operation against Iran. Qatar said on Monday its air force shot down two Iranian fighter jets.
The front month Nymex WTI crude contract was up by more than 5pc on Monday after retracing initial gains made on attacks from the US and Israel on Iran.
"What strikes me most of all this morning is the stark disparity between the risks that are facing global energy security because of this war in the Mideast Gulf and, apparently, the expectations of both the Trump administration and a lot of market participants," think tank Center for Strategic and International Studies senior fellow Clayton Seigle said in a webcast on Monday.
"Either the traders and the administration know something that we don't on the analyst side, that the situation is more benign than we're expecting, or we could be sleepwalking into triple digit oil prices pretty soon," Seigle said.
The senior civilian and military chiefs at the Pentagon, in a briefing earlier on Monday, described the US-Israeli military operation as proceeding as expected. The US military operations against Iran at the moment are prioritizing elimination of Tehran's long-range missile capacity, Joint Chiefs of Staff chairman, General Dan Caine said.
Trump's orders for the Pentagon are to "destroy Iranian offensive missiles, destroy Iranian missile production, destroy their navy and other security infrastructure, and they will never have nuclear weapons," defense secretary Pete Hegseth said.
"Our ambitions are not utopian," he said. "They are realistic, scoped to our interests and the defense of our people and our allies." Trump has offered Iran's military personnel 'immunity' if they surrender and has called on the people of Iran to "take advantage of this incredible opportunity", Hegseth said.
"This is not Iraq," he said. "This is not endless."
Hegseth did not rule out the possibility that US ground troops might be sent into Iran at some point. The Pentagon already is moving additional military resources to the Middle East, Caine said.
