A second round of nuclear talks between the United States and Iran are set for Saturday in Rome, Axios reports, after both sides cited positive and constructive opening dialogue in Oman last weekend.

The rival delegations in Oman say they achieved their objective of shifting from indirect to direct talks. By the end of it, Trump's regional envoy Steve Witkoff and Iranian Foreign Minister Abbas Araghchi briefly spoke in the presence of the Omani foreign minister.

The Trump administration reportedly wants the same format for the upcoming Rome talks. According to Axios, Witkoff and Arachchi's first interaction lasted for about 45 minutes, which was longer than expected. Axios further says:

The source described that conversation, the highest-level dialogue between U.S. and Iranian officials in eight years, as "substantive, serious and excellent."

But akin to slow-moving Ukraine peace talks, President Trump is already expressing frustration and warning Tehran than it better not just slow-walk the process of talks.

During comments to reporters in the Oval Office while meeting with El Salvador President Nayib Bukele on Monday, Trump repeated that threat of military action being on the table.

"Iran wants to deal with us, but they don’t know how. They really don’t know how. We had a meeting with them on Saturday. We have another meeting scheduled next Saturday, I said, ‘that’s a long time,’ so I think they might be tapping us along," he explained.

He continued, "If we have to do something very harsh, we’ll do it. And I’m not doing it for us. I’m doing it for the world. These are radicalized people, and they cannot have a nuclear weapon."

A reporter asked him if options include directly striking Iran's nuclear facilities, to which he responded, "Of course."

The Iranian side has said this is only the "beginning" of talks and diplomatic engagement with the new Trump administration. It has said it won't sign a simple replacement deal after the US withdrew from the 2015 JCPOA nuclear deal. It can no longer trust Washington, officials have made clear.

FM Baghaei has said, "The objective of the Islamic Republic of Iran is very clear — we have only one goal, and that is to safeguard Iran’s national interests."

"We are giving a genuine and honest opportunity to diplomacy, so that through dialogue, we can move forward on the nuclear issue on one hand, and more importantly for us, the lifting of sanctions," he added. 

But Witkoff days ago had previewed to The Wall Street Journal just ahead of the Oman trip, "I think our position begins with dismantlement of your program. That is our position today."

He described, "Where our red line will be, there can’t be weaponization of your nuclear capability." However Iran has maintained all along that its program is only for peaceful nuclear energy to meet the nation's power needs, and further several Ayatollah's have declared nuclear weapons to be 'unIslamic'.