WarWASHINGTON/TEHRAN — President Donald Trump said Monday that the US attack on Iran is meeting its goals ahead of schedule but also warned the war could go "far longer" than his initial estimates of about a month.

 

"We're already substantially ahead of our time projections," Trump said at the White House, adding, "From the beginning we projected four to five weeks, but we have capability to go far longer than that. We'll do it."

 

He said the strikes were the "last, best chance" to hit Iran, an arch foe of the United States for decades.

 

"Our objectives are clear," he told an event at the White House after US officials gave a changing variety of reasons for the US-Israeli offensive.

 

"First, we're destroying Iran's missile capabilities... Second, we're annihilating their navy... Third, we're ensuring that the world's number-one sponsor of terror can never obtain a nuclear weapon.

 

"Finally we are ensuring the Iranian regime can't continue to arm, fund and direct terrorist armies outside of their borders," he said.

 

Trump has previously justified the war saying that Iran was attempting to rebuild its nuclear programme and could soon have missiles able to strike the United States.

 

But he had not previously listed four reasons, including preventing Iran from supporting regional militant groups such Hizbollah and Hamas.

 

US and Israeli forces have so far struck hundreds of targets across Iran, including the Islamic republic's missiles, navy and command-and-control sites.

 

Trump on Monday said he is not ruling out sending US troops into Iran, while threatening a new, "big wave" of attacks.

 

The 79-year-old Republican has long campaigned against decades of US military entanglements in the Middle East, but ordered a large-scale war against Iran starting Saturday.

 

While so far the assault has focused entirely on aerial attacks by missiles and bombs, Trump refused to rule out sending ground troops -- something generally considered to be far riskier in terms of possible casualties.

 

"I don't have the yips with respect to boots on the ground -- like every president says, 'There will be no boots on the ground.' I don't say it," Trump told the New York Post in one of numerous brief interviews he has given since launching the Iran operation.

 

"I say 'probably don't need them,' [or] 'if they were necessary,'" he said.

 

Trump also spoke to CNN on Monday, flagging what he said would be an escalation in the assault on Iran.

 

"We haven't even started hitting them hard. The big wave hasn't even happened," he told CNN, without elaborating. "The big one is coming soon."

 

Two, four, six weeks?

 

Trump's comments came shortly after Defense Secretary Pete Hegseth also signaled that deploying troops inside Iran had not been ruled out.

 

Asked if there were already boots on the ground, Hegseth told a news conference: "No, but we're not going to go into the exercise of what we will or will not do."

 

"We'll go as far as we need to go," he said.

 

As for how long the war will last, Hegseth said: "Four weeks, two weeks, six weeks, it could move up. It could move back."

 

"No stupid rules of engagement, no nation building quagmire, no democracy-building exercise. No politically correct wars. We fight to win and we don't waste time or lives," the Pentagon chief said.

 

"This is not Iraq. This is not endless," Hegseth said. "Our generation knows better and so does this president. He called the last 20 years of nation building wars 'dumb' and he's right."

 

General Dan Caine, the top US military officer, spoke alongside Hegseth, saying that air superiority had been achieved over Iran.

 

Strikes by American forces "resulted in the establishment of local air superiority. This air superiority will not only enhance the protection of our forces, but also allow them to continue the work over Iran," Caine said.

 

Iran's Revolutionary Guards warned on Monday that the United States "will no longer be safe", on the third day of joint US-Israeli attacks against the Islamic republic.

 

"The enemy should know that their happy days are over and they will no longer be safe anywhere in the world, not even in their own homes," the Guards' Quds force, which oversees its foreign operations, said in a statement carried by state TV.

 

Iran's retaliatory strikes have so far targeted 500 sites linked to the United States and Israel in the Middle East, the Revolutionary Guards said on the third day of fighting Monday.

 

"Since the start of the conflict, the brave soldiers of the Iranian armed forces have attacked 60 strategic targets and 500 American military targets and targets of the Zionist regime [Israel]," the Guards said in a statement. It added they had launched more than 700 drones and hundreds of missiles.

 

The Revolutionary Guards also said on Monday that they had attacked an allegedly US-linked oil tanker in the Strait of Hormuz as part of a wave of strikes retaliating against a US-Israeli assault.

 

"The ATHE NOVA tanker, one of the American allies in the Strait of Hormuz, is still on fire after being hit by two drones," the Guards said in a statement. On Saturday, the Guards said they had closed the waterway, which is vital for oil and gas shipments, after the start of US and Israeli attacks.