US President Donald Trump said Tuesday the countries that have not joined the Middle East war but are struggling with fuel shortages should "go get your own oil" in the Strait of Hormuz. 

In a Truth Social post, Trump said countries "that refused to get involved" should "build up some delayed courage, go to the Strait, and just TAKE IT," adding that the United States would not help them.  

"The U.S.A. won't be there to help you anymore, just like you weren't there for us. Iran has been, essentially, decimated. The hard part is done. Go get your own oil!"

US Defense Secretary Pete Hegseth echoed that message during a news conference on Tuesday.

"This is an international waterway that we use less than most, in fact dramatically less than most," Hegseth said.

"It's not just our problem set, going forward, even though we have done the lion's share of preparation to ensure that that strait will be open," he said.

Hegseth also said that the next days of the Iran war will be "decisive," while refusing to rule out US ground forces playing a role in the conflict.

"The upcoming days will be decisive. Iran knows that, and there's almost nothing they can militarily do about it," Hegseth said.

Asked about concerns among some of President Donald Trump's base about the possible use of ground troops in Iran, Hegseth declined to tip his hand.

- Iran talks 'gaining strength' -

"You can't fight and win a war if you tell your adversary what you are willing to do, or what you are not willing to do, to include boots on the ground," he said.

"If we needed to, we could execute those options on behalf of the president of the United States and this department. Or maybe we don't have to use them at all -- maybe negotiations work," Hegseth said.

The Pentagon chief said talks on ending the war were making progress even as the more than month-long US-Israeli military campaign against the Islamic republic continued.

"They are very real. They are ongoing, they are active, and I think, gaining strength," Hegseth said of the negotiations.

He also said he had made an unannounced trip to visit US troops taking part in operations against Iran.

"We were on the ground in CENTCOM on Saturday for about half the day. For reasons of operational security, so those troops are not targeted, the places and bases will not be named," Hegseth said, referring to the US command responsible for the region.

"Suffice it to say, the trip was an honor. I had a chance to bear witness, and I witnessed the best of America," he said.

General Dan Caine -- the top US military officer -- spoke alongside Hegseth, saying that US forces have struck more than 11,000 targets so far.

The United States "continues to destroy Iran's ballistic missile and (drone) capabilities. We remain focused on interdicting and destroying the logistical and supply chains that feed these programs," he said.