Foreign Minister Abbas Araghchi said Wednesday that Iran's enrichment of uranium as part of its nuclear program was "non-negotiable" after US Special Envoy Steve Witkoff called for a halt.

Iran's supreme leader Ayatollah Ali Khamenei on Tuesday voiced satisfaction with recent talks with the United States, expressing confidence in the Islamic Republic's position but casting doubt on U.S. intentions.

The talks were "well carried out in the first steps. Of course, we are very pessimistic about the other side, but we are optimistic about our own capabilities," state TV quoted Khamenei as saying.

A second U.S. aircraft carrier is operating in Mideast waters ahead of the next round of talks between Iran and the United States over Tehran's rapidly advancing nuclear program, satellite photos analyzed Tuesday by The Associated Press showed.

The operation of the USS Carl Vinson and its strike group in the Arabian Sea comes as suspected U.S. airstrikes pounded parts of Yemen controlled by the Iranian-backed Houthi rebels overnight into Tuesday. American officials repeatedly have linked the U.S.' monthlong campaign against the Houthis under President Donald Trump as a means to pressure Iran in the negotiations.

Talks between Iran and the United States over Tehran's rapidly advancing nuclear program appeared ready to leave the Middle East on Monday, as an Italian source and others said the next round of negotiations would take place in Rome. But early Tuesday, Iran insisted the next round would again be held in Oman.

It wasn't immediately clear where the negotiations would be held after Tehran's overnight announcement. American officials have not said where the talks would be held. President Donald Trump separately complained Monday about the pace of nuclear talks between the United States and Iran as the two countries start a new round of pivotal negotiations.

Iran's Islamic Revolutionary Guard Corps said Tuesday the country's military capabilities were off limits, ahead of a second round of talks with the United States on its nuclear program.

"National security and defense and military power are among the red lines of the Islamic Republic of Iran, which cannot be discussed or negotiated under any circumstances," Guards spokesman Ali Mohammad Naini said, quoted by state broadcaster IRIB.

Russia on Monday claimed its deadly missile attack on Ukraine's Sumy that killed and wounded scores including children had targeted a gathering of Ukrainian troops, while European leaders condemned the attack as a war crime.

Ukrainian officials have said two ballistic missiles on Palm Sunday morning hit the heart of Sumy, a city about 30 kilometers (less than 20 miles) from Ukraine's border with Russia, killing at least 34, including two children, and wounding 119. It was the second large-scale attack to claim civilian lives in Ukraine in just over a week.

The Kremlin on Monday hailed last week's talks on the Ukraine conflict between President Vladimir Putin and Donald Trump's envoy Steve Witkoff.

"Such contacts are extremely useful and very effective," Kremlin spokesman Dmitry Peskov said, adding the talks in Saint Petersburg presented a "needed channel" through which Putin and Trump could pass information to each other.

French Interior Minister Bruno Retailleau was on a visit to Rabat on Monday, where he is expected to discuss security cooperation with his Moroccan counterpart Abdelouafi Laftit.

Talks will primarily focus on migration cooperation, the fight against organized crime and drug trafficking, according to the French interior ministry.

The head of the UN nuclear watchdog, Rafael Grossi, will arrive in Tehran on Wednesday for discussions with senior Iranian officials, state media reported, ahead of new round of talks between Iran and the United States.

During his visit, Grossi is set to meet Iranian Foreign Minister Abbas Araghchi and Mohammad Eslami, head of the Atomic Energy Organization of Iran (AEOI), the state news agency IRNA reported on Monday, citing Deputy Foreign Minister Kazem Gharibabadi.

President Donald Trump bitterly attacked "60 Minutes" shortly after the CBS newsmagazine broadcast stories on Ukraine and Greenland on Sunday, saying the network was out of control and should "pay a big price" for going after him.

"Almost every week, 60 Minutes ... mentions the name 'TRUMP' in a derogatory and defamatory way, but this Weekend's 'BROADCAST' tops them all," the president said on his Truth Social platform. He called on Federal Communications Commission Chairman Brendan Carr to impose maximum fines and punishment "for their unlawful and illegal behavior."