TEHRAN, Iran (AP) — The Iranian president lashed out at the United States on Monday as Iran marked the country's "National Nuclear Day," dedicated to its achievements in nuclear technology.

Hassan Rouhani said that despite many attempts, the U.S. has "failed to destroy" the landmark 2015 deal between Iran and world powers.

Rouhani also mocked President Donald Trump, who has repeatedly described the nuclear agreement as "bad." However, the U.S. president re-certified the deal in January but said the U.S. would not do the same in May, when the next deadline comes up.

"They spent huge amounts of dollars and talked a lot, and posted so many tweets, thinking that this building would shake with tweets," Rouhani said of the Trump administration officials. His speech was broadcast live on Iranian state TV.

The nuclear agreement curbed and set caps on Tehran's controversial nuclear enrichment program in exchange for relief from international sanctions.

Rouhani also reaffirmed his government's commitment to the deal and said Iran would not be the first to violate it. He also stressed Iran is ready to reverse quickly to the situation before the deal, should the U.S. abandon it.

"If they breach the deal, they will see its impacts within a week or less than a week," Rouhani said.

The spokesman for Iran's Atomic Agency, Behrouz Kamalvandi, claimed that should the deal collapse, Iran would be able to restart the enrichment program and enrich uranium to the level of 20 percent within two days. Weapons-grade uranium is 90 percent enriched.

Rouhani on Monday also unveiled dozens of Iran's purported nuclear achievements, including a centrifuge for use in the oil industry and a laser spectrometer.

Iran often boasts of technological achievements which are impossible to independently verify.

In his speech, Rouhani urged Arab countries in the Mideast — many of them Washington allies — to stop cooperating with the U.S. and turn to each other instead.

"Trust your nation's powers and the power of regional nations," he said. "Let's stand together."