ISLAMABAD — Qatar formally joined the Turkey-mediated peace talks here on Monday as an observer state, presenting mediators with a draft proposal for humanitarian corridors out of Iranian and Iraqi war zones and a parallel sub-track on detained nationals, in a move that broadened the diplomatic effort heading into what organizers had originally billed as the final day of the session.

The decision to admit Qatar, announced jointly by Turkish Foreign Minister Hakan Fidan and Pakistani Foreign Minister Ishaq Dar at a brief mid-morning availability, came after overnight consultations between Doha, Ankara, and Riyadh. Qatari Minister of State for Foreign Affairs Mohammed bin Abdulaziz Al-Khulaifi flew in shortly after dawn aboard a government aircraft and went directly into a session with Pakistani officials at the foreign ministry compound, according to a diplomat with knowledge of the schedule.

“Qatar comes to Islamabad not as a party but as a friend of all the parties,” Al-Khulaifi told reporters in a short statement on the steps of the ministry. “We bring with us a single proposal, narrowly drawn: that civilians displaced by this war and the families of those detained on all sides should not have to wait for a broader settlement to see relief.”

The Qatari draft, portions of which were described to reporters by two officials briefed on its contents, would establish three protected land corridors — one running from western Iran into eastern Iraq, one from southern Iraq toward Kuwait, and one connecting the Yemeni interior to Omani territory — through which civilians could pass without being subject to military targeting. The draft also proposes a Doha-based working group, chaired by Qatar with Swiss and International Committee of the Red Cross participation, to compile lists of foreign nationals detained by Iran since the war’s onset and of Iranian and Hezbollah-affiliated detainees held by U.S. and Israeli authorities.

Officials emphasized that the prisoner-issues track was being framed as a humanitarian rather than political channel, intended to operate in parallel with the main ceasefire negotiations rather than as a precondition for them. “We are very deliberately not calling this a prisoner exchange,” one Gulf official said, speaking on condition of anonymity to characterize the discussions candidly. “It is a list-building exercise. Whether and when names are matched is a later question.”

The expansion of the talks to include Qatar represented the first formal addition to the Islamabad framework since the inaugural session opened Saturday, and was widely read among diplomats here as a sign that the mediators were preparing the ground for a longer process than the original three-day agenda had suggested. Saudi Foreign Minister Prince Faisal bin Farhan Al Saud, asked whether Qatar’s arrival amounted to a Gulf consensus behind the talks, replied only that “the region speaks more clearly when it speaks together.”

China endorsed the framework from Beijing in a notably warm statement issued shortly before noon local time. Foreign Ministry spokesperson Mao Ning, at a regular briefing, said China “welcomes and supports” the Islamabad process, called for an “immediate, comprehensive and durable cessation of hostilities,” and indicated that Beijing was prepared to dispatch a senior envoy to the talks if invited by the mediators. The statement stopped short of a formal request to participate but represented the most substantive Chinese engagement with the diplomatic track since the war began.

Russian Foreign Minister Sergey Lavrov, by contrast, struck a more skeptical note in remarks to Russian state television. Lavrov said Moscow would “study with interest” the outcomes of the Islamabad session but criticized what he characterized as the marginalization of the United Nations Security Council in the mediation architecture. “It is not for any single regional grouping, however well-intentioned, to substitute itself for the legal mechanisms of the international community,” Lavrov said. He did not explicitly criticize Turkey or Pakistan.

Iranian Deputy Foreign Minister Majid Takht-Ravanchi, who has led Tehran’s delegation since Saturday, met privately with Al-Khulaifi for nearly two hours Monday morning, according to officials familiar with the schedule. In a brief statement issued afterward, the Iranian delegation said it “welcomed” the Qatari humanitarian proposal in principle but reiterated that “no parallel process can substitute for an immediate halt to Israeli airstrikes.”

Iranian Foreign Minister Abbas Araghchi, in Tehran, separately told the semiofficial Tasnim news agency that the Islamic Republic would “examine the Qatari paper seriously” but warned that “humanitarian gestures cannot wash away the responsibility of the aggressor.” Araghchi’s remarks suggested that Tehran was prepared to engage with the sub-track without softening its preconditions for engagement on the main ceasefire question.

The U.S. delegation, which has remained in observer status since the talks opened, did not comment publicly on the Qatari proposal. A senior State Department official, reached in Washington, said the administration was reviewing the draft and would coordinate its response with the Israeli government, which has continued to express skepticism that any negotiated framework can adequately address the threat posed by Iran’s nuclear program. “Humanitarian channels are one thing, and we will look at them on their merits,” the official said. “But the president has been clear that the strategic questions cannot be deferred.”

Layla Hassan, a Beirut-based regional analyst with the Carnegie Middle East Center, said Qatar’s entry into the process carried particular weight given Doha’s prior role in negotiations involving Hamas, the Taliban, and other actors that Western governments have at times declined to engage directly. “What Qatar brings is not influence over Tehran in the conventional sense,” Hassan said in a phone interview. “It is a track record of moving prisoners and bodies across lines that no one else can cross. That is the muscle memory the mediators want in the room.”

The closing news conference originally planned for late Monday afternoon was postponed, organizers said, to allow continued discussion of the Qatari draft and what Fidan described as “several other ideas that have come into the room over the weekend.” Officials said the talks would now continue into Tuesday at a minimum, with the possibility of extending through the week if the parties agreed.

Fidan, asked whether the expansion of the framework risked diluting its focus, said the opposite was true. “Every door we open is a door that does not have to be broken down later,” the Turkish minister said. “We are building rooms in this house, not tearing down walls.” Officials said additional working-level meetings would be announced in the coming days.