U.S. President Donald Trump has warned that the United States could resume military strikes on Iran if ongoing diplomatic efforts fail, while indicating there is little appetite in Washington to extend the current ceasefire.

Speaking in an interview with CNBC, Trump said he expects Tehran to participate in a new round of talks expected to be held in Islamabad, adding that the United States holds a strong negotiating position.

“I think we’re going to end up with a great deal,” he said. “I think we’re in a very strong negotiating position.”

However, the U.S. president struck a hard line when asked about the possibility of extending the temporary truce, saying time was limited and suggesting Washington is prepared to escalate if necessary.

“I don’t want to do that. We don’t have that much time,” Trump said, before warning that military action remains on the table if an agreement is not reached.

“I expect to be bombing because I think that’s a better attitude to go in with. But we’re ready to go. I mean, the military is raring to go,” he added.

Fragile diplomacy amid conflicting signals

Trump’s remarks come as uncertainty surrounds planned talks between U.S. and Iranian representatives, reportedly facilitated by Pakistan.

While Washington has indicated readiness to proceed, Iranian officials have publicly denied sending any delegation and reiterated that negotiations will not take place under threat or pressure.

Senior Iranian figures, including parliamentary leadership, have stressed that Tehran’s participation depends on a shift in U.S. policy, particularly the lifting of what they describe as coercive measures.

The diplomatic push follows a short-term ceasefire brokered earlier this month to halt escalating tensions between the two sides. The truce is due to expire in the coming days, raising concerns that hostilities could resume if no breakthrough is achieved.

Analysts say Trump’s refusal to consider an extension of the ceasefire reduces the already narrow window for diplomacy and increases the risk of renewed confrontation.

Pakistan has been attempting to mediate between the two sides, hosting initial indirect contacts and seeking to bring both parties back to the negotiating table. However, with positions hardening in both Washington and Tehran, the prospects for a deal remain uncertain.

The situation underscores the volatility of the region, where diplomatic efforts are racing against time to prevent a return to open conflict.

US Vice President JD Vance is expected to arrive in Islamabad on Wednesday to lead the second round of indirect talks involving Iran, according to sources close to the mediation process cited by Al Jazeera, amid growing uncertainty over whether the Iranian side will participate.

Sources said Vance will depart Washington on Tuesday evening and is expected to land in the Pakistani capital around midday on Wednesday, with the discussions reportedly scheduled to take place the same day.

Preparations for the meeting are said to be underway, with reports indicating that several US military aircraft have already arrived in Pakistan in connection with the arrangements for the delegation.

However, Iran’s participation remains unclear. Iranian state media has already denied reports that any delegation has travelled to Islamabad for talks, dismissing earlier speculation as “unfounded” and insisting that no representatives—senior or otherwise—are currently engaged in such negotiations.

Adding to the uncertainty, Iranian Parliament Speaker Mohammad Bagher Ghalibaf reiterated that Tehran does not accept negotiations conducted under threat or pressure, reinforcing long-standing Iranian conditions for any diplomatic engagement with Washington.

The apparent contradiction between US planning and Iranian public positions has raised doubts over whether the scheduled meeting will proceed as planned.

Pakistan, which has played a mediating role in facilitating earlier contacts between the two sides, is continuing efforts to keep the diplomatic channel open. However, observers note that the talks remain fragile, with both timing and participation still in question.

The situation comes at a sensitive moment, as broader regional tensions and ceasefire arrangements linked to earlier rounds of dialogue face increasing uncertainty.

Concerns are mounting over the durability of the ceasefire between the United States and Iran after Washington said it had seized an Iranian cargo vessel accused of breaching its maritime blockade, prompting a warning of retaliation from Tehran.

According to the U.S. military, forces opened fire on an Iranian-flagged ship following a prolonged standoff in waters near the Strait of Hormuz, disabling its engines before troops boarded the vessel. U.S. Central Command said marines descended from helicopters and took control of the ship.

U.S. President Donald Trump confirmed the operation in a social media post, saying American forces had “full custody” of the vessel and were inspecting its cargo.

Iranian authorities condemned the seizure, describing it as “armed piracy.” A military spokesperson, quoted by state media, warned that Iran’s armed forces would respond. Officials said the ship had been en route from China to the Iranian port of Bandar Abbas.

Ceasefire and talks in doubt

The incident has cast doubt on efforts to sustain a fragile ceasefire set to expire on Tuesday. Hopes for a broader agreement also appeared uncertain after Iranian state media reported that Tehran would not take part in a planned second round of negotiations.

Iranian officials cited ongoing U.S. blockade measures, escalating rhetoric, and what they described as shifting demands from Washington. First Vice President Mohammadreza Aref said Iran would not accept restrictions on its oil exports while others benefited from open energy markets.

“If Iran’s oil is restricted, others should not expect full security,” he said in remarks carried by state media.

Preparations for uncertain negotiations

Despite the tensions, diplomatic activity is continuing. U.S. envoys are expected to travel to Islamabad, which has been acting as a key mediator. However, uncertainty remains over the composition of the U.S. delegation and whether talks will proceed as planned.

Security measures in Islamabad have been stepped up ahead of the anticipated visit, with restrictions imposed on transport and heightened protection around key venues.

Iran’s parliament speaker Mohammad Baqer Qalibaf had earlier indicated that while some progress had been made in initial discussions, significant gaps remain, particularly over nuclear issues and maritime security.

Global market impact

The developments have unsettled global markets. Oil prices rose sharply amid fears that the ceasefire could collapse, further disrupting flows through the Strait of Hormuz — a critical route for roughly one-fifth of the world’s oil supply.

The conflict, now in its eighth week, has already caused major disruptions to regional energy production. Countries including Saudi Arabia, Iraq, Kuwait and the United Arab Emirates have seen significant declines in output.

Escalating rhetoric

Tensions have been further heightened by increasingly sharp rhetoric. President Trump has warned that the United States could target key Iranian infrastructure if negotiations fail, while Iranian officials have threatened retaliatory strikes against regional energy and utility facilities if attacked.

The war, which began in late February, has triggered one of the most severe shocks to global energy markets in recent history and raised fears of broader regional escalation.