Uncertainty surrounds the second round of US-Iran talks expected in Islamabad, as intensified diplomatic activity and conflicting signals from both sides cast doubt over the negotiations, sources said on Tuesday.

Media reports indicate that US Vice President J.D. Vance is likely to arrive in Islamabad with senior officials for high-stakes discussions.

However, Iranian authorities have suggested they will not participate under what they describe as coercive conditions.

Iranian officials accused the US of violating the ceasefire, pointing out the seizure of an Iranian cargo vessel by the US forces in the Sea of Oman and the continued naval blockade of its ports.

Iranian officials argue that such actions undermine the basis for meaningful dialogue.

At the same time, Donald Trump has offered mixed messages about the path forward. While expressing confidence that negotiations will proceed in Pakistan, he has also indicated there is no urgency to conclude the conflict, which has reportedly caused significant casualties in Iran and driven up global oil prices.

With a 14-day ceasefire set to expire on Wednesday, Trump has alternated between optimism about a potential deal and stark warnings of escalation if no agreement is reached.

In recent remarks, he suggested that failure to secure a deal could result in intensified military action.

Despite the tensions, Trump said he still intends to send a negotiating team led by Vice President Vance to Islamabad. Iran, however, maintains it will not engage unless Washington eases its demands.

Iran’s chief negotiator and parliament speaker, Mohammad Baqer Qalibaf, accused the United States of attempting to force Tehran into submission, warning instead that Iran is prepared to escalate if necessary.

“We do not accept negotiations under the shadow of threats,” Qalibaf said in a post on X.

Trump, meanwhile, reiterated that he faces no pressure to end the conflict unless Iran agrees to US terms, stating that developments could unfold quickly.

He also expressed confidence that Tehran would ultimately come to the negotiating table, warning that failure to do so would bring severe consequences.

Trump added that any agreement must ensure Iran is permanently prevented from acquiring nuclear weapons, which he described as a global security concern.