Ukraine Presses New Offensive as Russian Troops Retreat From Kharkiv RegionUkrainian forces advanced their counteroffensive in eastern Ukraine Sunday, looking to take advantage of Russian troop withdrawals from the northeastern Kharkiv region in a retreat that may have changed the course of the nearly seven-month conflict. Ukrainian President Volodymyr Zelenskyy derided the Russians in his nightly video address Saturday, saying, “The Russian army in these days is demonstrating the best that it can do — showing its back."\n\nOn Sunday, he posted a video of Ukrainian soldiers hoisting the national flag over Chkalovsk, one of several towns they reclaimed from the Russians in the counteroffensive.\n\nUkraine's military chief, Gen. Valerii Zaluzhnyi, said that Ukraine had reclaimed about 3,000 square kilometers from Moscow’s forces since the beginning of September. He said Ukrainian troops are now just 50 kilometers away from the border with Russia. SEE ALSO: The battlefield advance marked the biggest Ukrainian success since early in the war when it thwarted a Russian attempt to seize the capital, Kyiv. Ukraine's attack in the Kharkiv region seemed to surprise Moscow, which had moved many of its troops from the area to the south, where Kyiv had publicly announced a counteroffensive. Russia’s Defense Ministry, in response to the Ukrainian gains, said Saturday the troops' withdrawal from Izyum and other areas in the Kharkiv region was intended to strengthen Russian forces in the neighboring Donetsk region to the south. But the retreat drew angry comments from Russian military bloggers and nationalist commentators, who characterized it as a major defeat and urged the Kremlin to bolster war efforts. They criticized Russian authorities for staging fireworks and other lavish festivities in Moscow that marked a city holiday Saturday.\n\nIn its assessment, Britain’s Defense Ministry said Ukrainian forces have continued to make significant gains in the Kharkiv region. The agency’s intelligence report, posted Sunday on Twitter, said, “Russia has likely withdrawn units from the area, but fighting continues around the strategically important cities of Kupiansk and Izyum.” Western military analysts said if the advances are confirmed, it would put the Ukrainians in control of a main railway that Moscow has used to supply thousands of troops in eastern Ukraine. In other developments, a pro-Russia separatist leader was quoted as saying there also was fierce fighting between Russian and Ukrainian forces in the Donetsk region. Denis Pushilin said the situation in the town of Lyman was “very difficult” and there was fighting in “a number of other localities,” particularly in the northern part of the region. Military analysts say Russia is believed to be sending reinforcements to the area, where it plans to launch new attacks against Ukrainian-controlled sections of Donetsk. Meanwhile, Moscow announced it was regrouping its forces in the eastern Kharkiv region of Ukraine. “To achieve the goals of the special military operation to liberate Donbas, a decision was made to regroup Russian troops stationed in the Balakliya and Izyum regions, to bolster efforts along the Donetsk front,” Russia's Defense Ministry said in a statement. The regrouping of Russian soldiers comes as residents in parts of the Kharkiv region had been advised to evacuate to Russia, according to the state-run news agency Tass. The area’s Russian-installed administrator, Vitaly Ganchev, reportedly said doing so would “save lives.” The Ukrainian breakthrough near Kharkiv was the fastest advance reported by either side for months, and it is one of the biggest gains in the war since Russian forces abandoned its efforts to capture Kyiv. On the diplomatic front, German Foreign Minister Annalena Baerbock made a surprise visit to Kyiv Saturday, pledging Berlin's unwavering support for Ukraine. “I have traveled to Kyiv to show that they can continue to rely on us. That we will continue to stand by Ukraine for as long as necessary with deliveries of weapons, and with humanitarian and financial support,” Baerbock said in a statement. Over the last weeks, Germany has sent howitzers, rocket launchers and anti-aircraft missiles to Ukraine. Heavier weapons such as anti-aircraft systems, rocket launchers mounted on pickup trucks and anti-drone equipment are also expected in a further military aid package worth more than $500 million. Some information in this report came from Reuters, Agence France-Presse and The Associated Press.