Why the Iran-US ceasefire is falling apart

International mediators have proposed a 10-day ceasefire between the United States and Iran, according to a senior Iranian official cited in reports. The measure is described as intended to reduce hostilities and allow renewed talks on a prior interim agreement.

Both sides are assessing next steps in the current regional security situation.

Reports indicate that a US-Iran ceasefire has broken down amid renewed fighting, with the potential impact of mediation efforts by Pakistan, Qatar, and Oman remaining unclear. Earlier diplomatic steps included a June memorandum of understanding between the parties for further negotiations and talks hosted in Geneva in February.

The summary also references Europe’s historical role in diplomacy, including the 1814-15 Congress of Vienna.

Donald Trump stated in a Fox News interview that his representatives had spoken with Iranian officials an hour earlier and that those officials wanted to make a deal to end the conflict, though he noted they had broken prior agreements and expressed uncertainty about whether one would be reached.

He added that people do not want to die and that Iran would need to proceed carefully to avoid further losses. The remarks come amid an ongoing US-Iran conflict that has involved casualties and shipping disruptions in the Strait of Hormuz, with some social media users criticizing the repetition of similar statements.

A file photo of Sun Lei, China's deputy permanent representative to the United Nations, speaking at a United Nations Security Council meeting, New York, US, December 23, 2025. /VCG A file photo of Sun Lei, China's deputy permanent representative to the United Nations, speaking at a United Nations Security Council meeting, New York, US, December 23, 2025.

/VCG China on Friday called for efforts to preserve the ceasefire and prevent further escalation in the Middle East, stressing that dialogue and diplomacy remain the only viable path to resolving the Iran nuclear issue. Speaking at an open meeting of the UN Security Council on the Iran nuclear issue on Friday, Sun Lei, China's deputy permanent representative to the United Nations, said tensions in the region had eased temporarily after the United States and Iran signed a memorandum of understanding (MoU), but the ceasefire situation has since faced setbacks and prospects for negotiations remain complicated.

"The proper resolution of the Iran nuclear issue bears on whether the Middle East can return to peace and stability, as well as the common interests of the international community," Sun said. He urged all relevant parties to advance negotiations with a rational and pragmatic approach.

Sun noted that under the MoU, the United States and Iran committed to respecting each other's sovereignty and territorial integrity, permanently halting military activities on all fronts, and establishing a roadmap for negotiations and sanctions relief.

China called on all parties to remove obstacles, refrain from resorting to force or threatening the use of force, and uphold and implement the outcomes of the MoU, Sun said. He also urged efforts to reach a solution that addresses the concerns of all sides, lift sanctions against Iran as soon as possible, and make substantive progress toward a political settlement.

Sun stressed that resolving the Iran nuclear issue requires respecting the legitimate concerns and lawful rights of all parties. "Iran should continue to uphold its commitment not to develop nuclear weapons, while its legitimate right to the peaceful use of nuclear energy should be respected," he said.

Sun called on the United States to take concrete actions to create conditions for a political solution, adding that the Security Council's immediate priority should be to maintain an objective and impartial stance, provide time and space for diplomatic efforts, and create a favorable environment for negotiations.

He stressed that the UN Security Council should not become a tool for individual countries to advance their political agendas or exert pressure. Before the meeting began, the Russian representative said that the UN Security Council Resolution 2231, which endorsed the Joint Comprehensive Plan of Action (JCPOA) on Iran's nuclear program, had expired and that the Iran nuclear issue had been removed from the Council's agenda.

Russia requested a procedural vote on whether to proceed with the meeting. Sun later spoke in support of Russia's position. Sun said China has repeatedly stated that Resolution 2231 expired on October 18, 2025, after which the Security Council terminated its consideration of the Iran nuclear issue and the UN secretary-general should stop submitting related reports.

"The current situation in the Middle East and the Iran nuclear issue are at a critical juncture. The Security Council should play a constructive role in promoting negotiations and easing tensions," Sun said. He expressed concern that some Security Council members had insisted on holding a meeting under an agenda item that had already been terminated, claiming to support diplomatic efforts.

Such actions, he said, would not only deepen divisions within the Security Council, but also undermine the atmosphere for negotiations and seriously hinder a political resolution of the Iran nuclear issue. China urged relevant countries to stop political manipulation at the Security Council, implement the termination provisions of Resolution 2231, safeguard the authority of the Council and the credibility of multilateral diplomacy, and create favorable conditions for a political settlement.

China voted against the procedural motion on the meeting agenda.