Basking in the afterglow of his apparently constructive meeting with North Korean leader Kim Jong Un, President Donald Trump said that he'd soon like a "real deal" with the U.S.' other long-time enemy Iran.

Speaking to reporters following a historic meeting with Kim, at which the regime's leader signed an agreement that appeared to commit to the "complete denuclearization of the Korean Peninsula," Trump said he hoped relations could also improve, in time, with Iran.

"I hope that, at the appropriate time, after the sanctions kick in — and they are brutal what we've put on Iran — I hope that they're going to come back and negotiate a real deal because I'd love to be able to do that but right now it's too soon to do that," Trump said.

Relations between the U.S. and Iran started to sour as soon as Trump was elected to the presidency in November 2016, having called an accord to limit Iran's nuclear capabilities — brokered by his predecessor, Barack Obama, and other world powers — a "terrible deal."

Trump followed through on a threat to withdraw the U.S. from the deal in May and said sanctions would be re-imposed on Iran.

Penalties to be re-imposed by August 6 include sanctions on Iran buying or acquiring U.S. dollars, trading gold and other precious metals, sanctions on its sale, supply or trade of metals such as aluminum and steel, as well as sanctions on issuing Iranian debt and its auto sector.

Further sanctions to come later this year will affect Iran's shipping, financial and oil sectors.

Needless to say, the sanctions are expected to damage Iran's economy, with Trump himself describing the sanctions as "brutal" on Tuesday. He added though that a decline in confidence might make the country's officials think about negotiating another deal with the U.S.

"On the Iran deal, I think Iran is a different country now than it was three or four months ago. I don't think they're looking so much to the Mediterranean, I don't think they're looking so much at Syria like they were, with total confidence, I don't think they're so confident right now," he said.

Not long after Trump and Kim's agreement was announced, Iran warned North Korea not to trust the U.S. president who, it said, could cancel their denuclearization agreement within hours.

"We don't know what type of person the North Korean leader is negotiating with. It is not clear that he would not cancel the agreement before returning back home," Iran's government spokesman, Mohammad Bagher Nobakht, said, according to Reuters who quoted the IRNA news agency.