KRAKOW, Poland — Facing deeper isolation by the day over the Ukraine war, Russia seemed to slightly recalibrate its stance Thursday, allowing greater humanitarian access to the devastated port city of Mariupol and apparently retreating from a payment confrontation with European gas customers.
But Western officials said they saw little evidence to support Russia’s claims that it was greatly reducing its military presence around Kyiv, Ukraine’s capital, and fighting continued unabated in areas around the city on Thursday. In Dnipro, the central city that has become a hub for humanitarian aid to other parts of Ukraine, a Russian attack overnight destroyed an oil terminal, a local official said.
“Russia maintains pressure on Kyiv and other cities, so we can expect additional offensive actions, bringing even more suffering,” the NATO general secretary general, Jens Stoltenberg, said at a news conference.
Whatever Moscow’s real intentions on the battlefield, Russian officials scoffed Thursday at American claims a day earlier that subordinates of President Vladimir V. Putin, fearing his wrath, were misleading him about how the war was going.
“They do not understand President Putin,” said the Kremlin spokesman, Dmitri S. Peskov. “They do not understand the decision-making mechanism and they do not understand the efforts of our work.”
In Mariupol, where the population has, for weeks, been cut off from the outside world by heavy Russian bombardment and intense fighting, a respite appeared possible amid reports that a team from the International Committee of the Red Cross was preparing to try to enter the city. The group hoped to deliver emergency humanitarian aid and begin evacuating residents on Friday.
“There seems to be a glimmer of hope we might be able to go, so we need to be close,” said Crystal Wells, a spokeswoman for the Red Cross in Geneva.
Thousands of civilians are believed to have died, and survivors have been trapped in basements without heat or electricity, and desperately short of food, water and other essentials.
Ukraine’s deputy prime minister, Iryna Vereshchuk, said Thursday that a convoy of 45 buses had departed for Mariupol to reach trapped civilians, and that an agreement had been reached on a passageway for evacuating people from the city of Melitopol, farther west.
People from both cities were expected to make their way to Zaporizhzhia, a city farther north that remains under Ukrainian control, although evacuations in previous days have been sporadic and have often been scrapped at the last minute because of fighting.
The Russians also appeared to show some leeway on Mr. Putin’s demand that European customers of his country’s natural gas now pay in rubles, or risk a cutoff. European governments, which rely heavily on Russian gas imports, had rejected this new condition, arguing that it violated purchase contracts.
After speaking with the Russian leader, the prime minister of Italy, Mario Draghi, said he did not believe that Europe was “in danger” of having its gas supply halted. He said that he understood that the Russian president would grant a “concession” to European countries, and that the conversion of payments from dollars or euros into rubles was “an internal matter of the Russian Federation.”
Russia also said Thursday that its forces were leaving the defunct Chernobyl Nuclear Power Plant, according to a statement from Ukraine’s state-run energy company. Chernobyl, site of the worst nuclear accident in history, had been occupied by Russian forces since the war’s early days.
Asked about unconfirmed reports that some Russian soldiers had suffered radiation sickness, the Pentagon press secretary, John F. Kirby, said the troop movement appeared to be part of a broader repositioning and not from “health hazards or some sort of emergency or a crisis at Chernobyl.”
Both Ukrainian and Russian officials signaled a willingness to keep negotiating over how to end the war, now in its sixth week. A member of Ukraine’s negotiating team said that discussions would resume via video link on Friday, and the foreign minister of Turkey, which hosted talks this week, said that his Russian and Ukrainian counterparts could meet within weeks.
And on Thursday, Turkey’s president, Recep Tayyip Erdogan, offered cautious backing to a proposal circulating in European corridors of power that might help bring about a peace agreement. In principle, Mr. Erdogan said, Turkey could help guarantee Ukraine’s security.
During peace talks earlier this week in Istanbul, Ukrainian officials said their country was ready to concede a key demand from Moscow and declare itself permanently neutral, forsaking hopes of joining NATO. Ukrainian negotiators also said they were willing to discuss Russian territorial claims.
But the Ukrainians said they would make the concessions only in return for security guarantees from a group of other nations.
Ukrainian officials envision an arrangement in which a group of countries — potentially including NATO members like the United States, Britain, Turkey, France and Germany — would commit to defending Ukraine.
On Thursday, a Ukrainian negotiator, Mykhailo Podolyak, suggested to a Turkish broadcaster that the so-called guarantor countries would have legal obligations to provide weapons, military personnel or financial help if conflict involving Ukraine erupted again.
“This is the meaning of this pact: A country that considers an attack will know that Ukraine is not alone,” he said.
The big question was whether Moscow, which has repeatedly objected to what it calls NATO encroachment, finds this palatable.
Russia-Ukraine War: Key Developments
Despite Russian claims that the war was proceeding according to plan, the Kremlin is said to be struggling with problems in its military, which has made far less headway in Ukraine than Western experts had once expected.
On Thursday, the director of Britain’s electronic surveillance agency, Jeremy Fleming, said the Russian forces, hampered by low morale and weapons shortages, had accidentally shot down their own aircraft and had refused to carry out orders.
But in Russia itself, Mr. Putin’s approval ratings have reached levels unseen in years, according to a Russian poll released on Thursday, as many Russians rally around the flag in the face of sanctions and other international pressure.
Although the credibility of the poll might be questionable — especially since Mr. Putin has severely limited free expression since the war — it was conducted by the Levada Center, one of the few independent pollster groups left in Russia.
“The confrontation with the West has consolidated people,” said Denis Volkov, the center’s director.
While they generally did not support Mr. Putin, some respondents said that now was the time to do so.
People believe that “everyone is against us” and that “Putin defends us; otherwise, we would be eaten alive,” Mr. Volkov said.
The war’s destructive ripple effects have spilled over into marketplaces around the world.
Both Ukraine and Russia are major providers of the world’s wheat, corn and barley, but Ukrainian agricultural officials said Thursday that more than 16 million tons of grain had been stranded in the country, and that Ukraine had missed out on at least $1.5 billion in exports. Earlier in the week, the U.S. State Department’s No. 2 official warned at a U.N. Security Council meeting that the war posed “immediate and dangerous implications for global food security.”
With fuel costs soaring over sanctions on Russian oil, the U.S. government announced a plan to release up to 180 million barrels from strategic reserves over the next six months to enlarge the supply and ease prices.
Still, the Biden administration made clear that it would expand the sanctions on Russia as part of the American-led effort to cripple the Russian economy as punishment for the Ukraine invasion.
In Washington, the Treasury Department on Thursday leveled new sanctions on Russian technology companies and what it called illicit procurement networks that Russia is using to evade existing sanctions.
“We will continue to target Putin’s war machine with sanctions from every angle until this senseless war of choice is over,” the Treasury secretary, Janet L. Yellen, said in a statement.
Megan Specia reported from Krakow, Poland, Anton Troianovski from Istanbul and Steven Erlanger from Brussels. Reporting was contributed by Patricia Cohen from London, Nick Cumming-Bruce from Geneva, Dan Bilefsky from Montreal, Melissa Eddy from Berlin, and Alan Rappeport from Washington.