Steve Witkoff and Jared Kushner, Trump's son-in-law, mediated the talks in the Emirati capital — the first direct discussions between Moscow and Kyiv in nine months. The sessions ended Wednesday without a major breakthrough, yielding only an agreement to exchange a large number of prisoners, with the exact figure still to be announced.

After the Abu Dhabi talks, Kushner and Witkoff traveled directly to Moscow to brief Putin. The meeting at the Senate Palace lasted about two hours. The envoys are scheduled to fly to Dublin for talks with Ukrainian President Volodymyr Zelenskyy as the war approaches its five-year mark.

Kushner said one goal of the Kremlin meeting was to secure Putin's consent for European representatives to join the negotiations, which are examining the continent's broader security architecture. Washington and Kyiv want Europe to appoint a single negotiator to deal with Moscow.

But Russia has resisted direct European involvement, arguing that European countries are financing and supplying Ukraine's military. European capitals, in turn, are wary of Russia's intentions on the continent. Many European leaders view Moscow's inclusion in discussions about postwar security as an unwelcome concession to Putin, who has long described NATO's eastward expansion as a primary threat and has demanded that the alliance pull its troops back from Russia's borders.

Some analysts suggest negotiators may be considering concessions on NATO strategy in exchange for peace in Ukraine — a prospect that alarms European leaders.

Kushner said the Russian and Ukrainian delegations in Abu Dhabi "agreed on many of the principles, but are still apart on some of the way to accomplish" peace.

Putin reiterated to the U.S. envoys that any European troops deployed to Ukraine after a ceasefire would be "absolutely unacceptable." Russia would treat such a deployment as a security threat and a legitimate target, he said. "In other words, the war would resume immediately."

He also said Russia considers its border with Ukraine — as sealed by a prospective peace deal — to now extend over the four Ukrainian regions Moscow annexed in 2022 but never fully controlled.

Zelenskyy, speaking in Dublin ahead of a summit of more than 40 European countries, said political shifts could create "a window of opportunity" for a settlement. He pointed to Democrats taking control of the U.S. Congress in January following midterm elections and elections in France next year.

"The political landscape in Europe could change in 2027. … We also see changes already taking place in the United States," Zelenskyy said late Wednesday.

He called the proposed prisoner exchange a positive step but insisted Ukraine will not surrender Russian-occupied territory in exchange for peace. Russia and Ukraine have swapped prisoners occasionally, but the two sides remain far apart on the terms for a settlement.

NATO Secretary-General Mark Rutte, who is also attending the Dublin summit, said the United States, Europe and Ukraine are "very much aligned" on what security guarantees should look like following a meeting in Paris in January. "But now of course we need the peace deal, or at least a ceasefire," Rutte said.

Amid the diplomacy, fighting continues along the roughly 1,200-kilometer (750-mile) front line. Russia's larger army has been held back by determined Ukrainian resistance, while Moscow's drone and missile strikes on Ukraine's energy infrastructure have disrupted heat, electricity and water supplies to cities — a campaign Kyiv calls a "weaponization of winter."

Russia's Defense Ministry said its air defenses downed 71 Ukrainian drones overnight and that its forces struck a drone-manufacturing plant in Kyiv and three other facilities producing missile fuel and drone components near the capital. Ukraine's air force said Russia launched missiles and 123 drones, 73 of them jet-powered, at Ukraine overnight, with hits recorded at 17 locations.

Zelenskyy said Thursday on social media that Ukraine is experiencing another slowdown in the U.S. Starshield system — SpaceX's military-grade version of the Starlink satellite internet service — that the country relies on to defend against Russian attacks. Military units have recorded "significant disruptions," including speed restrictions limiting Ukrainian drones to 161 kph (100 mph), he said, adding that a military investigation determined the restrictions were not random errors.

Ukraine uses Starlink and Starshield to intercept Russian drones and launch its own strikes. Last month, limits on Ukrainian drone speeds severely disrupted operations and alarmed Kyiv officials who fear U.S. support could drop off. Elon Musk acknowledged that SpaceX had throttled the Starlink service in Ukraine for about a week, saying the system could not be used for offensive strikes against Russia.

Zelenskyy said in Dublin that the speed limits cover operations in Russian-occupied parts of Ukraine and that Kyiv is trying to determine from U.S. officials what is happening. "If someone in America is making decisions that basically treat Ukrainian territory as if it is not Ukrainian, then this tells us where things are going," he said.

In St. Petersburg, a Russian serviceman was killed early Thursday when his vehicle exploded, according to Russia's Investigative Committee, the country's main criminal investigation agency. The committee did not identify the victim or say who was behind the bombing. The Fontanka news outlet reported that the victim was a colonel and that a bomb in his car detonated as he drove off. Several senior Russian military officers have been killed in bombings and other attacks that Moscow blames on Ukraine; Kyiv has claimed responsibility for some attacks on Russian soil.