U.S. President Donald Trump said here on Monday that he is ready to meet with Iranian President Hassan Rouhani without preconditions.

"I'd meet with anybody. I believe in meeting," Trump told a joint news conference with visiting Italian Prime Minister Giuseppe Conte, when asked whether he was willing to meet with the Iranian leader.

Touting his "great" meetings with the top leader of the Democratic People's Republic of Korea, Kim Jong Un, Russian President Vladimir Putin, and leaders of NATO, Trump said such meetings had led to good results.

"I would certainly meet with Iran if they wanted to meet. I don't know that they're ready yet. I ended the Iran deal. It was a ridiculous deal," Trump said. "I do believe that they will probably end up wanting to meet, and I'm ready to meet anytime they want to."

"If we could work something out that's meaningful, not the waste of paper that the other deal was, I would certainly be willing to meet," he added.

"They want to meet, I'll meet. Any time they want. Good for the country. Good for them. Good for us. And good for the world," he said.

Relations of the two nations have been at odds as the Trump administration pulled the United States out of the historic 2015 Iran nuclear deal in May. Washington ramped up political pressure on Tehran and vowed to re-impose sanctions on the nation.

In 2015, Iran and five permanent members of the UN Security Council- Britain, China, France, Russia and the United States - plus Germany, signed the deal in Vienna. Under the accord, Iran agreed to limit its sensitive nuclear activities and allow international inspectors to examine in return for the lifting of crippling economic sanctions.

Hours before Trump's statement, Iran's foreign ministry ruled out the possibility of negotiations with the U.S. government over the enduring bilateral problems.

"The United States has proved that it is unreliable, so engagement and dialogue with the current U.S. government is impossible," Foreign Ministry spokesman Bahram Qasemi said earlier on Monday.