Hopes for a diplomatic resolution to the US-Israeli war with Iran flickered briefly before fading over the weekend as direct talks between US and Iranian officials in Islamabad ended without agreement, leaving tensions in the Middle East elevated amid continued exchanges of threats.

The 21-hour negotiations in Pakistan, the first face-to-face talks between the US and Iran at this level since the 1979 Islamic Revolution, broke down over core differences on Iran's nuclear program and control of the Strait of Hormuz, a critical chokepoint for global oil flows.

US Vice President JD Vance, leading the American delegation alongside special envoy Steve Witkoff and Jared Kushner, said his team had not seen a clear commitment that Iran will neither pursue a nuclear weapon nor acquire the means to rapidly build one. Iranian officials countered that US conditions were excessive and failed to respect Tehran's right to peaceful nuclear activities.

The failed talks followed a six-week war that tested Iran’s resilience and brought the Middle East to the brink, as US and Israeli strikes hit military targets, senior Iranian officials, and nuclear facilities. The campaign, however, has done little to ease US concerns over Iran’s nuclear program, with Tehran still believed to possess centrifuges and a stockpile of near weapons-grade enriched uranium estimated in the hundreds of kilograms. Iran has consistently maintained that its nuclear program is for peaceful purposes.

Prospects for reaching an agreement remain alive, for now. Pakistan, which helped broker the ceasefire, has proposed a second round of talks in Islamabad this week, while Trump said on Monday that Iranian officials had reached out expressing interest in a deal, even as a US blockade of Iranian ports threatened to escalate tensions.

Ali Vaez, Iran project director at the International Crisis Group think tank, said the talks highlight the wide gaps between the two sides, but that he did not expect an immediate breakdown.

"The path forward, if there is one, lies in a limited, reciprocal deal that buys time and lowers the temperature," he told AP.

Any future deal would likely center on strict limits on enrichment levels, robust International Atomic Energy Agency (IAEA) monitoring and phased lifting of sanctions. The gap remains wide but not unbridgeable. Reports say Iran has floated suspending enrichment for up to five years and diluting its highly enriched uranium, while the US has pushed for a 20-year moratorium and full removal of the stockpile.

Analysts say some US demands are non-starters for Iran, questioning whether Trump administration officials clearly understand its position.

"On a political level, Iran views enrichment as an issue of national sovereignty, a right conferred by the peaceful uses of nuclear energy provision (in Article IV) of the nuclear Nonproliferation Treaty," Thomas Hajnoczi, a former Austrian ambassador to the UN, wrote in an article published by Arms Control Association, a US-based think tank.

"It is consistent with Iran's past position for negotiators to reject any nuclear agreement if the price was zero enrichment," he wrote in March.

Yet translating any technical or diplomatic opening into a concrete agreement will depend heavily on whether both sides can navigate intense domestic pressures. Iran's leadership faces internal pressure to demonstrate resilience after weeks of bombardment and economic strain from sanctions and disrupted oil exports. The Trump administration is balancing demands from Israel and Gulf partners for stringent curbs on Tehran against the risks of prolonged conflict and higher global energy prices.

Attention is now shifting to the durability of the fragile ceasefire, which is set to expire next week. While hostilities have largely paused, tensions remain elevated, with the US naval blockade of Iranian ports and continued military posturing raising the risk of renewed confrontation.

The coming days will test whether mediators can bridge the divide or if military and economic pressure will dictate the next phase. For now, the path toward a stable nuclear arrangement looks long and uncertain.