Ukrainian officials have downgraded the chances of significant progress in the talks, which are set to take place in Istanbul, after Turkish President Tayyip Erdogan spoke with Russian President Vladimir Putin on Sunday. But the fact that they took place in person – for the first time since a tough meeting between the foreign ministers on March 10 – was a sign of behind-the-scenes change as Russia’s invasion has stalled. Sign up now for FREE unlimited access to Reuters.com Register On the ground, there was no sign of rest for civilians in the besieged cities, especially in the devastated port of Mariupol, whose mayor said 160,000 people were still trapped inside and Russia was blocking evacuation efforts. The Kremlin, for its part, said it was concerned by remarks by US President Joe Biden, who said in a speech on Saturday that President Vladimir Putin should not remain in power. Russia and Ukraine have said their delegations will arrive in Turkey on Monday, with talks expected to begin on Tuesday. Ukrainian officials recently suggested that Russia might now be more willing to compromise, as any hopes it could have of a new government in Kyiv were met with fierce Ukrainian resistance and heavy Russian losses. The Russian military signaled last week that it was shifting its focus to expand separatist-held territory in eastern Ukraine, a month after deploying most of its enormous invasion force in a failed attack in Kyiv. When the two sides last met in person, Ukraine accused Russian Foreign Minister Sergei Lavrov of ignoring calls to discuss a ceasefire, while Lavrov said a ceasefire was not even on the agenda. Since then, they have met repeatedly via video rather than face-to-face. Both sides have publicly discussed a formula under which Ukraine can accept some form of formal neutrality. But neither has given in to Russia’s territorial claims, including Crimea, which Moscow annexed and annexed in 2014, and the eastern territories known as Donbass, which Moscow is seeking to cede to the separatists. “I do not think there will be progress on the main issues,” Ukrainian Interior Ministry adviser Vadim Denishenko said on Monday. In an interview with Russian journalists at the weekend, Ukrainian President Volodymyr Zelenskiy mentioned some form of compromise concerning Donbas, although he did not suggest that this could entail the transfer of territory. In his final comments overnight, he made it clear that “territorial integrity” remained Kiev’s priority. MEASURED RESPONSE TO THE BIDEN CALL The Kremlin, which regularly denounces the West for Ukraine, has so far given only a measured response to Biden’s surprise at the weekend over an end to Putin’s 22-year rule, perhaps to avoid drawing attention to it. The President of Ukraine Volodymyr Zelenskiy attends a video interview with some of the Russian media, as the Russian attack on Ukraine continues, in Kyiv, Ukraine, March 27, 2022. Press Service of the President of Ukraine / Information via REUTERS read more “In the name of God, this man can not stay in power,” Biden said Saturday at the end of a crowd address in Warsaw. Washington and NATO have stressed that Putin’s ouster is not US or allied policy, and Biden said on Sunday that he did not call for regime change. Asked Monday about Biden’s comment, Kremlin spokesman Dmitry Peshkov said: “This is a statement that is certainly worrying.” “We will continue to monitor the US president’s statements more closely,” Peshkov told reporters. Earlier, Peshkov had said that it was up to the Russian people to choose their leader. Russia calls its actions in Ukraine a “special military operation” to disarm and “disarm” its neighbor. Kyiv and the West see it as a pretext for an unprovoked invasion. From the outset, Western countries have stated that they believed that Russia’s real goal was to overthrow the Kiev government quickly, something that Moscow had failed to do. Last week, Ukrainian forces launched an offensive, repelling Russian troops in areas around Kyiv, northeast and southwest. Russia, meanwhile, has continued to push to the southeast near separatist areas, including the catastrophic siege of Mariupol, which has been razed to the ground, while tens of thousands of civilians remain trapped inside. Mayor Vadym Boichenko, who has fled the city and was speaking from an unknown location, said 26 buses were waiting to evacuate some of the 160,000 trapped civilians, but that Russia was denying safe passage. “The situation in the city remains difficult. People are beyond the bounds of humanitarian catastrophe,” Boychenko told national television. “We must completely evacuate Mariupol.” Deputy Prime Minister of Ukraine Iryna Vereshchuk said there were no plans to open corridors to evacuate civilians from besieged cities on Monday, amid reports of possible Russian “provocations” along the route. Elsewhere, Russia’s armored personnel carriers have struggled with supply problems and made little or no progress despite pounding in residential areas. “As of today, the enemy is regrouping its forces, but they can not move anywhere in Ukraine,” Ukrainian Deputy Defense Minister Hanna Malyar said on Monday. The British Ministry of Defense also said that there has been no significant change in Russia’s position in the last 24 hours, with most Russian gains near Mariupol and fierce fighting taking place there. The General Staff of Ukraine stated that the Kiev defense forces are holding back the Russian troops that are trying to break through from the northeast and northwest and occupy main roads and settlements. In the south, Ukrainian forces focused on defending the cities of Krivy Rih, Zaporizhzhia and Mykolayiv. Sign up now for FREE unlimited access to Reuters.com Register Report from Reuters’s offices. Writes Peter Graff. Edited by Gareth Jones Our role models: The Thomson Reuters Trust Principles.