For more than a year, Russia has pounded Ukraine’s power grid with a barrage of cruise missiles and drone strikes, causing irreparable damage to power stations and rolling blackouts across the country. Meanwhile, Ukraine has struck Russia’s oil facilities with long-range drone attacks that have set ablaze refineries, depots and reservoirs, reducing Moscow’s oil refining by an estimated 15 percent and raising gas prices around the world.

Some involved in the negotiations hoped they could lead to a more comprehensive agreement to end the war, according to the officials who like others spoke on the condition of anonymity to discuss the sensitive diplomacy.

The diplomat briefed on the talks said Kyiv and Moscow had both signaled their readiness to accept the arrangement in the lead-up to the summit. But senior officials in Kyiv had mixed expectations about whether the negotiations could succeed, with some putting the odds at 20 percent and others anticipating even worse prospects, according to two people familiar with the talks, even if the Kursk assault had not happened. But the planned talks and potential agreement — now on hold — raise the stakes for Zelensky’s gamble.

One of the reasons Ukrainian officials doubted Russia’s sincerity is its extensive bombing campaign of Ukrainian energy infrastructure in recent weeks. More bombardment could leave civilians without power for hours each day during the frigid winter months.

“We have one chance to get through this winter, and that’s if the Russians won’t launch any new attacks on the grid,” an Ukrainian official who was briefed on the talks said.

Kyiv’s move to push into Russia, which has occupied roughly 20 percent of Ukraine, was intended in part to give Ukraine more leverage for any future negotiations, Ukrainian and Western officials have said.

Military analysts have expressed skepticism that Ukrainian forces can maintain control of the Russian territory. Moscow has also continued to make gains in eastern Ukraine’s Donetsk region and has not diverted troops from there to defend the new Ukrainian assault.

But while Kyiv might have improved its future negotiating position with the land grab, the likelihood of imminent peace talks appears diminished. Putin publicly vowed this week not to soften his position on negotiations because of the assault on Russian territory.

The diplomat familiar with the talks said that Qatar has been discussing the arrangement for an energy strike moratorium with Kyiv and Moscow for the past two months. The official said the two sides agreed to a summit in Doha with just minor details left to be worked out.

“After Kursk, the Russians balked,” another person familiar with the talks said.

A Russian academic with close ties to senior Russian diplomats signaled that Putin would not be in the mood to make a deal after the Kursk offensive.

“You know our Russian leadership usually does not make any compromises under pressure,” the person said.

The academic added that Russia might be more willing to consider an energy infrastructure deal as a way to lure Kyiv to broader cease-fire talks. Otherwise, he said, Moscow could be less motivated since it believed it could inflict more damage on Ukrainian energy infrastructure than Kyiv was able to on Russian oil refineries.

Russia’s strikes on Ukraine’s power grid have been a brutally effective tactic. Daily life for Ukrainians who live far from the front line has been disrupted by blackoutsthat can last hours. The outages have also severely hurt an economy already crippled by war. Some people who have moved abroad cite the power instability as a chief reason.