WASHINGTON -- US President Donald Trump took an executive action Tuesday to restore the so-called "maximum pressure" campaign on Iran aimed at preventing the Islamic Republic from obtaining nuclear weapon.

Speaking to reporters in the Oval Office as he was signing the document -- of which the exact content and form the White House has yet to make public -- Trump said he took the action somewhat hesitantly, adding that he hoped the measure would lead to a negotiated deal with Tehran.

"So this is one that I'm torn about. Everybody wants me to sign it. I'll do that. It's very tough on Iran," Trump said. "We will see whether or not we can arrange or work out a deal with Iran."

"So I'm signing this and I'm unhappy to do it, but I really have not so much choice because we have to be strong and firm," the president went on. "I mean, we're going to see they cannot have a nuclear weapon with me. It's very simple. Iran cannot have a nuclear weapon."

Trump took the action shortly before he met in the White House with Israeli Prime Minister Benjamin Netanyahu, one of whose goals during the visit in Washington is to call on the Trump administration to exert more pressure on Iran.

Later, sitting side-by-side with Netanyahu in the Oval Office, Trump responded to an Iran-related question from the press by claiming that the country was left "in big trouble" when his first term ended, only to become "very strong right now" due to what he said was failed Middle East policy by the Joe Biden administration.

"We're not going to allow them to have a nuclear weapon. It's very simple. You know, I signed a very strong proclamation," Trump said.