JERUSALEM—With President Donald Trump set to leave for the Middle East on Monday, talks between the U.S. and the Islamic Republic of Iran concluded a fourth round of negotiations in Oman on Sunday over Tehran’s illicit nuclear weapons program. 

A day before the start of talks, Iranian Supreme Leader Ali Khamenei welcomed chants of “Death to America” in Tehran. “Your judgment is right,” Khamenei told a crowd of supporters who called for the destruction of the U.S.

Iranian Foreign Ministry spokesperson Esmail Baghaei said the nuclear talks were “difficult but useful.” A U.S. official, speaking on condition of anonymity to discuss the closed-door negotiations, offered a little bit more, describing them as being both indirect and direct, The Associated Press reported.

An “agreement was reached to move forward with the talks to continue working through technical elements,” the U.S. official said. “We are encouraged by today’s outcome and look forward to our next meeting, which will happen in the near future.”

President Donald Trump arrives on Air Force One at Joint Base Andrews, Maryland, on Sunday, May 4, 2025. (AP Photo/Manuel Balce Ceneta)

The hot-button issue of uranium enrichment has plagued talks with Iran over the last few decades. The Europeans faced intense criticism when they agreed—independent of the U.S.—to allow the Islamic Republic to enrich uranium during the nascent phase of atomic talks during the early years of this century.

Brodsky said “The original sin of U.S. decision-making on Iran’s nuclear program was when the Obama administration changed the U.S. position from zero enrichment to tolerating enrichment at 3.67%. That laid the groundwork for Iran to retain the capability to continue to use its nuclear program to extort the United States and ultimately build a nuclear weapon.”

The nuclear expert noted, “That should end today, and recent comments from President Trump, Special Envoy Witkoff, and Secretary Rubio hopefully signal that this era is over. House and Senate Republicans were also very clear on this point over the last week. The Iranians say they want a durable deal. But a JCPOA 2.0—tolerating enrichment at 3.67% and no dismantlement of nuclear facilities—would not be one.

“The Iranians are engaged in all kinds of gimmicks to dress up a variation of the same concessions they offered to President Obama. That should be unacceptable to American negotiators.”

An Iranian military truck carries surface-to-air missiles past a portrait of Iran’s Supreme Leader Ayatollah Ali Khamenei during a parade on the occasion of the country’s annual army day on April 18, 2018 in Tehran, Iran. (ATTA KENARE/AFP via Getty Images)

The anti-American news outlet, Kayhan, that serves as the mouthpiece for Khamenei, published a full-page screed against Trump where it stated, “He is a framework based on narcissism, superiority delusions, and threat-based tactics.”

The talks on Sunday ran for some three hours in Muscat, the capital of Oman. Iran’s regime spokesperson, Baghaei, said that a decision on the next round of talks is under discussion.

The Associated Press contributed to this report.