Iran’s top negotiator, Mohammad Bagher Ghalibaf, declared late Monday that Tehran will not negotiate with the United States “under the shadow of threats,” warning Tehran is prepared to “reveal new cards on the battlefield” as a ceasefire deadline looms and the fate of renewed talks remains uncertain.

Speaking in a post on X, Ghalibaf — who has led Iran’s recent negotiations alongside Iranian Foreign Minister Abbas Araghchi — accused President Donald Trump of attempting to turn diplomacy into “an instrument of surrender” through continued pressure, including a U.S. naval blockade.

“Trump, by imposing a siege and violating the ceasefire, seeks to turn this negotiating table — in his own imagination — into a table of surrender or to justify renewed warmongering,” Ghalibaf wrote. “We do not accept negotiations under the shadow of threats, and in the past two weeks, we have prepared to reveal new cards on the battlefield.”

Ghalibaf’s remarks underscored a hardening stance in Tehran just hours after conflicting signals earlier Monday suggested talks could proceed — only to be thrown into doubt again by Monday night.

A senior Pakistani official told Reuters earlier Monday that Islamabad had received a “positive signal” from Iran and was working to bring both sides to talks “tomorrow or a day after,” as mediation efforts intensified ahead of the looming deadline.

But by Monday night, Iranian officials signaled the opposite. Iranian Foreign Ministry spokesman Esmail Baghaei said there was currently “no plan” for a new round of negotiations and warned Washington would face a “decisive response” if it continued what Tehran described as ceasefire violations, including the naval blockade.

Iranian President Masoud Pezeshkian similarly accused the United States of sending “unconstructive and contradictory signals,” warning that Washington appears to be seeking Iran’s surrender — “something Iranians will never accept.”

Iranian Deputy Foreign Minister Saeed Khatibzadeh added Monday that Tehran “will not accept anything beyond international law,” warning that time pressure will not force concessions.

Iranian political analyst Seyed Mohammad Marandi, speaking in remarks amplified by Iranian state-linked outlets, said there had been “no inclination in the past few hours” to proceed, advising U.S. Vice President JD Vance to “unpack his suitcases” and not travel to Islamabad under current conditions.

At the same time, reporting from Axios late Monday indicated the situation remained fluid, with U.S. officials waiting for a definitive signal from Tehran. According to sources cited by the outlet, Iranian negotiators have been stalling amid pressure from the Islamic Revolutionary Guard Corps to hold a firmer line — insisting there be no talks without an end to the U.S. naval blockade.

The report added that the Iranian team had been waiting for a green light from the country’s supreme leader, which one source said came Monday night, though no public confirmation followed.

Axios further reported that Vice President JD Vance was expected to depart for Islamabad on Tuesday morning, with two sources saying he would leave then and a third suggesting he could depart late Monday night, alongside Special Envoy Steve Witkoff and Jared Kushner.

Earlier Monday, Trump said Vance was heading to Islamabad, though officials later clarified he remained in Washington at the time, underscoring the uncertainty surrounding whether or not talks will proceed.

The diplomatic uncertainty comes as the two-week ceasefire between the United States and Iran — announced by Trump on April 7 — is set to expire Wednesday at 8 p.m. Eastern time.

Trump made clear in remarks Monday, including in a phone interview with Bloomberg, that he is not inclined to extend the ceasefire without a deal. He said an extension is “highly unlikely,” while telling PBS News that if negotiations fail, “lots of bombs start going off.”

He also stressed Monday that he is “under no pressure whatsoever” to reach a deal, writing on Truth Social that he would not be rushed into an agreement that is “not as good as it could have been,” and warning Iran would face consequences “like they’ve never seen before” if it refuses to negotiate.

Tensions have also been inflamed by maritime incidents, including a U.S. interception of an Iranian-flagged vessel in the Sea of Oman on Sunday, which Tehran described as a violation of the ceasefire.

With both sides digging in and no clear confirmation that talks will proceed, the window for diplomacy appears to be narrowing rapidly as the ceasefire deadline approaches — raising the prospect that hostilities could resume within days if no agreement is reached, despite last-minute diplomatic movement.

Joshua Klein is a reporter for Breitbart News. Email him at jklein@breitbart.com. Follow him on Twitter @JoshuaKlein.