The sixth round of U.S.-Iran nuclear talks will be held on Sunday in Muscat, the Omani foreign minister said on Thursday, after U.S. President Donald Trump reiterated that Tehran would not be allowed to have a nuclear weapon.

The strike comes after President Donald Trump said the U.S. was "fairly close" to reaching a nuclear deal with Iran.

As the head of the secretive Islamic Revolutionary Guard Corps (IRGC) Major General Hossein Salami, was one of the most powerful men in Iran, overseeing its most potent military arm and reporting directly to its Supreme Leader Ayatollah Ali Khamenei.

Iran's stance directly clashes with U.S. President Donald Trump 's position that Iran must halt all enrichment amid negotiations marked by uncertainty, despite having reached their most significant step since they began in April with a U.S. offer being delivered to Tehran last week.

CNBC’s “Power Lunch” is joined by Helima Croft, head of commodity strategy at RBC Capital Markets, to discuss oil markets, tensions rising in the Middle East and more.

Iran has warned it will ramp up its nuclear activities after the United Nations nuclear watchdog’s 35-member board of governors adopted a resolution Thursday declaring it in breach of its non-proliferation obligations.

The US envoy is expected to arrive in Oman next week to participate in the sixth round of nuclear talks between the US and Iran, even as the US prepapres to evacuate nonessential personal for its Baghdad embassy.

The IAEA is expected to vote on a draft resolution stating that Iran has not provided answers and is violating commitments regarding the nuclear agreement.