Tensions in the Gulf have surged following a direct US naval strike on an Iranian-flagged cargo ship on Sunday and Tehran's subsequent refusal to engage in a new round of negotiations.

New round of US-Iran talks in doubt

The prospect of renewed dialogue between Washington and Tehran has grown increasingly uncertain.

The White House Sunday confirmed that senior US officials, including Vice President J.D. Vance, were expected to participate in a new round of talks in Islamabad, alongside special envoy Steve Witkoff and US President Donald Trump's son-in-law Jared Kushner.

Trump earlier indicated that an agreement could prompt his own visit to Pakistan, while also suggesting that negotiations remain fluid.

Tehran, however, has rejected reports of a second round of talks altogether. Iranian officials cited what they described as excessive US demands, inconsistent positions, and continued military pressure, including maritime actions, as key obstacles. Under such conditions, Iran argued, the prospects for meaningful progress remain dim.

At the same time, Iranian sources warned that the likelihood of renewed conflict may now exceed that of continued negotiations. Tehran has signaled that it is fully prepared for escalation, framing recent US military movements as either psychological pressure or a potential cover for future attacks.

Strait of Hormuz remains in focus

The situation in the Strait of Hormuz has become a central flashpoint. On Sunday, US forces intercepted and opened fire on an Iranian cargo ship in the Gulf of Oman, disabling the vessel before boarding it. Washington described the operation as enforcement of a maritime blockade, while Tehran condemned it as a violation of a ceasefire agreement and an act of aggression.

"Today, an Iranian-flagged cargo ship named TOUSKA, nearly 900 feet long and weighing almost as much as an aircraft carrier, tried to get past our Naval Blockade, and it did not go well for them," Trump wrote in a post on his social media Truth Social.

A US destroyer intercepted the TOUSKA in the Gulf of Oman, and "gave them fair warning to stop," Trump added. "The Iranian crew refused to listen, so our Navy ship stopped them right in their tracks by blowing a hole in the engine room. Right now, US Marines have custody of the vessel."

Iran has attacked US military vessels in retaliation for the US seizure of its ship, according to latest news reports.

Earlier, Iran's Khatam al-Anbiya Central Headquarters warned that it would "soon respond" to the US "armed maritime piracy," according to Iran's Press TV.

The incident has further heightened tensions around one of the world's most critical energy corridors. According to a report released by Windward, a London-based maritime analytics firm, a total of 35 vessels transited the strait on Saturday, including eight inbound ships – four tankers, two bulk carriers and two cargo vessels – and 27 outbound ships, comprising eight tankers, three bulk carriers, 15 cargo vessels and one passenger vessel.

Meanwhile, Iran is moving to formalize tighter control over the strait. Proposed legislation would restrict passage for vessels linked to Israel and prohibit transit by countries deemed hostile without prior authorization. Additional provisions could require payments in Iranian currency and impose penalties on states accused of harming Iran.

Mutual accusations of bad faith

The latest escalation has been accompanied by intensified rhetoric. Trump earlier accused Iran of firing on ships in the Strait of Hormuz, calling it a "total violation" of the ceasefire in a Truth Social post.

He warned of severe consequences if Tehran refuses what he called a "fair and reasonable" agreement, including potential strikes on critical infrastructure.

Iranian officials rejected these claims, accusing the United States of breaching the ceasefire through its maritime blockade and labeling such actions as illegal under international law.

Iranian Foreign Ministry spokesperson Esmaeil Baghaei said the US so-called blockade of Iran's ports and coastlines violated the ceasefire, calling it "unlawful and criminal."

"The United States' so-called 'blockade' of Iran's ports or coastline is not only a violation of Pakistani-mediated ceasefire but also both unlawful and criminal. It violates Article 2(4) of the UN Charter; it constitutes an act of aggression under Article 3(c) of the UN General Assembly Resolution 3314 (1974), which explicitly includes the blockade of a state's ports or coasts among such acts ... it amounts to a war crime and crime against humanity," Baghaei said in a post on X on Sunday.

Israel: Operations against Iran not over

Israel has reinforced the confrontational backdrop by signaling that its campaign against Iran is ongoing. Prime Minister Benjamin Netanyahu stated that joint objectives with the US have yet to be achieved and warned that developments could shift rapidly in the coming days.

His remarks suggest continued coordination between Israel and the US, while also pointing to the possibility of further military actions that could widen the scope of the conflict.