Deep-rooted differences over critical issues, particularly Iran's nuclear program and the scope of US sanctions, remain difficult to reconcile, leaving the prospects for future talks clouded by considerable uncertainty, experts say.

Iran's Foreign Minister Seyed Abbas Araghchi said on Saturday that he expects a new round of talks with the United States to take place "soon", describing the meeting held a day earlier as a positive start while cautioning that rebuilding trust would take time.

Although both sides signaled a willingness to continue negotiations, the US has maintained military pressure on Iran while further tightening economic sanctions. In response, Tehran has stepped up its own military deterrence posture toward Washington.

Speaking to a forum in Tehran on Sunday, Araghchi said Washington's continuation of sanctions on Iran and its recent military deployments "raise doubts about the other party's seriousness and readiness to engage in genuine negotiations".

During the talks in Muscat, Oman, on Friday, Iran reiterated that it will not relinquish what it calls its inalienable right to enrich uranium and rejected curbs on its missile program.

In an interview with Al Jazeera aired on Saturday, Araghchi said Iran is open to an agreement that reassures the international community while preserving its enrichment activities.

He rejected US demands that Iran curb its missile program, calling it a defensive matter that is "never negotiable".

US President Donald Trump described the Oman talks as "very positive" aboard Air Force One en route to his resort in Florida, saying the two sides would meet again this week.

On Friday, Trump signed an executive order, threatening additional tariffs on countries that continue to trade with Iran.

Ding Long, a professor at the Middle East Studies Institute of Shanghai International Studies University, said both Iran and the US appear to be pursuing a pressure-driven strategy to strengthen their military and economic leverage, enhance deterrence, accumulate bargaining chips and improve their negotiating positions.

"Both are adopting a hedging strategy in their negotiations, meaning that should talks break down, they can swiftly shift to military confrontation or even conflict," Ding said.

Sun Degang, director of the Center for Middle Eastern Studies at Fudan University in Shanghai, said both sides remain deeply divided on a range of core issues, making it difficult for the negotiations to achieve meaningful or substantive progress.

The core US demands on Iran include prohibiting the development of nuclear weapons, ending uranium enrichment and the possession of enriched uranium, imposing limits on ballistic missile ranges, and halting support for so-called regional proxy forces, he said.

Iran has said it does not seek nuclear weapons and asserts its inalienable right to pursuing peaceful nuclear energy. In the current negotiations, Tehran has consistently insisted that discussions focus exclusively on nuclear issues and sanctions relief, rejecting the inclusion of its missile program and regional activities on the agenda. These contrasting positions highlight the substantial gap between the two sides, Sun said.

Meanwhile, Israel is closely monitoring the negotiations. Prime Minister Benjamin Netanyahu's office said on Saturday that he would travel to Washington to hold discussions with US officials. The office said Netanyahu maintains that any agreement must include restrictions on Iran's ballistic missile program and an end to its support for allied militant groups.

Ding said: "Israel is the party most reluctant to see a US-Iran agreement materialize. It will spare no effort to undermine, obstruct and delay the peace talks, and may resort to its old tactics, such as in June when it launched military strikes against Iran just as a deal seemed imminent."

Other countries in the Middle East are unwilling to see conflict erupt between the US and Iran, fearing it would undermine regional security and derail development efforts, he said.

"These countries are expected to continue playing a constructive role, seeking to help both parties move toward a mutual nonaggression understanding," he said.

Agencies contributed to this story.

liujianqiao@chinadaily.com.cn