ISTANBUL, June 2 (Xinhua) -- Ukrainian and Russian delegations made modest but concrete progress in renewed peace talks in Istanbul on Monday, raising cautious hopes for a potential easing of hostilities through expanded humanitarian measures, including the largest prisoner exchange since the onset of the conflict.

The roughly 90-minute session marked the second round of direct talks between the two sides in recent weeks. Turkish officials described the outcome as "cautiously optimistic."

"The talks did not end negatively," Turkish Foreign Ministry spokesperson Oncu Keceli said, characterising the tone as constructive despite persistent divisions over the broader conflict.

AGREEMENTS ON HUMANITARIAN MEASURES

Turkish Foreign Minister Hakan Fidan, who chaired the negotiations, said on the social media platform X that the delegations built on previously agreed points, including measures related to humanitarian exchanges.

"There is an agreement on new categories and an increased number of prisoner swaps," Fidan said.

Ukrainian Defense Minister Rustem Umerov, leading Kiev's delegation, proposed a 30-day unconditional ceasefire, the return of displaced children and young soldiers, and the release of prisoners. Umerov called for "real efforts to end the war," and suggested holding a third round of talks between June 20 and 30, as part of a broader push toward a possible leaders' summit.

Russia's delegation, led by Presidential Aide Vladimir Medinsky, confirmed agreement on what he described as the largest prisoner exchange since the conflict began. "All severely wounded and seriously ill soldiers will be exchanged, along with all captured servicemen under the age of 25," he said.

Medinsky added that Moscow would return the bodies of 6,000 Ukrainian soldiers and proposed a two- to three-day ceasefire in specific front-line areas to enable body recovery. He also confirmed that discussions on the return of displaced Ukrainian children were underway, with Kiev submitting a list of 339 names. "We will work on this," he said.

Medinsky noted that a preliminary meeting with Umerov had helped set the stage for Monday's negotiations.

INTERNATIONAL REACTIONS

The United Nations (UN) welcomed the progress on humanitarian issues. "We obviously welcome any agreement that will bring the exchange of prisoners or remains," said UN spokesperson Stephane Dujarric.

Turkish President Recep Tayyip Erdogan hailed the meeting as a "significant achievement," saying the number of prisoners exchanged had surpassed 1,000, with some bodies returned outside formal channels. Erdogan also said Trkiye was prepared to host a high-level summit involving Russian President Vladimir Putin, Ukrainian President Volodymyr Zelensky, and potentially U.S. President Donald Trump.

Russian media, citing unnamed sources, reported that the next round of talks was likely to be held again in Istanbul.

TALKS SHADOWED BY ESCALATING AIRSTRIKES

The renewed negotiations come amid a backdrop of intensified military actions. Ukrainian officials said more than 40 Russian warplanes were damaged or destroyed in a drone strike on Sunday that targeted air bases deep inside Russian territory, including in the Arctic, Siberia, and Far East regions.

Vasyl Malyuk, head of Ukraine's Security Service, described the operation, which hit sites in three time zones simultaneously, as "a major slap in the face to Russia's military power." Ukrainian officials claimed nearly a third of Moscow's strategic bomber fleet was either destroyed or rendered inoperable.

The Russian Defense Ministry accused the "Kiev regime" of launching first-person-view drone attacks on multiple airfields. It said airstrips in the Ivanovo, Ryazan, and Amur regions were targeted, but that the strikes were repelled. Fires at airfields in the Murmansk and Irkutsk regions were extinguished, with no casualties reported.

In Washington, White House Press Secretary Karoline Leavitt said that Trump believes the conflict in Ukraine "needs to come to an end."