Politico - President Donald Trump on Saturday said any meeting with the Iranian regime is "up to them."

"Iran, and it�s economy, is going very bad, and fast! I will meet, or not meet, it doesn�t matter - it is up to them!" Trump wrote on Twitter while en route to Ohio for a political rally.

Secretary of State Mike Pompeo said earlier this week that such a summit would only come once the Iranians satisfy certain preconditions, including a willingness to reopen a deal on its nuclear program.

Trump's statement to reporters on Monday that he would meet with Tehran without preconditions caught commentators off guard, as the president had been increasingly hostile to the Islamic Republic.

On July 22, Trump threatened Iranian President Hassan Rouhani with an all-caps tweet.

"To Iranian President Rouhani: NEVER, EVER THREATEN THE UNITED STATES AGAIN OR YOU WILL SUFFER CONSEQUENCES THE LIKES OF WHICH FEW THROUGHOUT HISTORY HAVE EVER SUFFERED BEFORE," Trump wrote. "WE ARE NO LONGER A COUNTRY THAT WILL STAND FOR YOUR DEMENTED WORDS OF VIOLENCE & DEATH. BE CAUTIOUS!"

The president's comments on Monday sparked comparisons to North Korea, another nation that Trump threatened in harsh terms before agreeing to a meeting with its leader, Kim Jong Un.

"I would certainly meet with Iran if they wanted to meet," Trump said during a press conference with Italian Prime Minister Giuseppe Conte. "If they want to meet, I'll meet."

Pompeo later said he agreed with the sentiment, but appeared to add preconditions to any talks.

"If the Iranians demonstrate a commitment to make fundamental changes in how they treat their own people � reduce their maligned behavior, can agree that it's worthwhile to enter in a nuclear agreement that actually prevents proliferation, then the president said he's prepared to sit down and have a conversation with him,� Pompeo said on CNBC on Monday.

Iran continues to be at loggerheads with the U.S., especially over its nuclear program. Fulfilling a campaign promise, Trump pulled the U.S. out of an Obama-era accord involving Iran, the U.S., the EU and five other countries where nuclear-related sanctions would be lifted if the country scaled back its nuclear program.

Trump also defended his administration's tariffs on American allies and China, as concerns mount among farm-state lawmakers that tariffs will have a negative impact on the U.S.

"Tariffs are working far better than anyone ever anticipated," the president wrote on Twitter, adding "other countries use Tariffs against, but when we use them, foolish people scream!"