Storyline: The sixth round of indirect nuclear talks between Iran and the United States will take place in the Omani capital Muscat on Sunday, said Iran's Foreign Ministry early Tuesday. Iran and the United States have held five rounds of Oman-mediated indirect talks -- three in Muscat and two in Rome -- since April on Tehran's nuclear program and the lifting of U.S. sanctions. The fifth round was held on May 23 in Rome. In late May, the United States presented a proposal to Iran through Oman for a potential nuclear deal with the country. Iranian Foreign Ministry Spokesman Esmaeil Baghaei said the U.S. proposal was not the outcome of the previous rounds of negotiations, and that Iran would submit its proposal to the United States through Oman. He stressed that any proposal disrespecting Iran's national rights, including its right to the peaceful use of nuclear energy and effective sanctions relief, is unacceptable. Baghaei said Iran's forthcoming proposal would be "reasonable, logically sound, and balanced," urging the United States to consider it seriously. "Accepting this proposal serves the interests of the United States," he added. On the same day, the U.S. side made some remarks that were not conducive to the negotiations. U.S. President Donald Trump said that Iran is a tough negotiator. A U.S. official said that Iran is delaying the talks so that it could continue its nuclear program. Shotlist: FILE: Tehran, Iran - Date Unknown: 1. Various of national flags of Iran, cityscape, traffic FILE: Tehran, Iran - March 2024: 2. Various of Azadi Tower FILE: Iran - Date Unknown: 3. Various of traffic, national flags of Iran FILE: Muscat, Oman - Feb 23, 2025: 4. Oman's Foreign Ministry building, national flag of Oman FILE: Muscat, Oman - Date Unknown: 5. Sultan Qaboos Grand Mosque Rome, Italy - May 23, 2025: 6. Iranian delegation departing, media staff Rome, Italy - May 22, 2025: 7. Various of Omani Embassy in Italy, Omani national flag FILE: Washington D.C., USA - October 2024: 8. Various of White House 9. Various of Capitol building, U.S. national flag. [Restrictions: No access Chinese mainland/Al-Arabiya/Persian language TV Stations outside Iran. Strictly No Access BBC Persian/VOA Persian/Manoto TV/Iran International TV]