UK: Russia Suffers Highest Rate of Casualties Since First Week of InvasionKYIV, UKRAINE/WASHINGTON — The British Defense Ministry said Sunday that over the past two weeks, Russia has likely suffered its highest rate of casualties since the first week of the invasion of Ukraine, nearly one year ago. The ministry’s observation is based on Ukrainian data saying that the mean average of Russian casualties over the last seven days was 824 per day, representing more than four times the average reported for June and July. The ministry said the statistics are based on “likely accurate” Ukrainian data. The uptick in Russian casualties, the ministry said, is “likely due” to several factors, including lack of trained personnel, coordination and resources at the front. SEE ALSO: The U.K. intelligence update, posted on Twitter, also said Ukraine continues to experience a high attrition rate. Russia’s war against Ukraine could continue indefinitely, predicted the leader of the Russian paramilitary organization, Wagner Group. In a video interview, Yevgeny Prigozhin said late Friday it could take 18 months to two years for Russia to take full control of Ukraine’s eastern industrial heartland of Donbas. Prigozhin then said the war could extend for three years if Moscow decides to capture broader territories east of the Dnieper River. The British Defense Ministry said Saturday that data from the Russian Federal Penal Service suggested a drop-off in the rate of prisoner recruitment by the paramilitary group since December 2022. It said news of the “harsh realities” of service in Wagner in Ukraine has probably “filtered through to inmates and reduced the number of volunteers." The British ministry also said Russia is now facing a “difficult choice” of whether to continue “to deplete its forces, scale back objectives, or conduct a further form of mobilization.” The General Staff of Ukraine’s Armed Forces reported Saturday that Moscow is strengthening its grouping of troops near Lyman and Bakhmut in the eastern Donetsk oblast, and Russian forces are continuing to focus their key efforts on offensive operations in the directions of Kupiansk, Lyman, Bakhmut, Avdiivka, and Novopavlivsk in Ukraine's east and northeast. 'Mixed picture' In a briefing Friday at the Center for a New American Security, Celeste Wallander, the assistant secretary of defense for international security affairs, said Russia's military overall "is a mixed picture." She said as Russia continues to suffer losses in Ukraine, it is also applying lessons learned tactically, operationally, and somewhat strategically to adapt. "We're seeing some of those play out in how Russia's conducting, for example, the operations right now in Bakhmut in eastern Ukraine," she said. Wallander emphasized that Russia has "a deep bench of personnel" it can draw upon, and she said Russia "will remain a militarily capable adversary that we have to right size our plans, our operations and our capabilities to cope with." She expressed confidence that "Russia will not achieve its strategic or even its operational objectives, and we are confident that the Ukrainian armed forces are up to the task of defending its country." The White House announced Friday that U.S. President Joe Biden will travel to Poland on Feb. 20 to meet with Polish President Andrzej Duda and Eastern European allies. Coming just before the first anniversary of Russia's invasion of Ukraine on Feb. 24, Biden's visit "will make it very clear that the United States will continue to stand with Ukraine for as long as it takes," said John Kirby, spokesperson for the White House National Security Council. The announcement came after Russia's heavy shelling Friday, targeted civilians and civilian infrastructure and caused new power outages. Additional weaponry The attacks on Ukraine on Friday renewed calls for more weapons aid to Ukraine. European Council President Charles Michel said the missile barrage constituted war crimes. Western countries that have provided Ukraine with arms have so far refused to send fighter jets or long-range weapons capable of striking deep inside Russia. In an interview with Ani Chkhikvadze of VOA's Georgian Service, senior presidential adviser Mykhailo Podolyak said that negotiations are underway "not only on long-range weapons but also about aviation and not only for fighter jets." President Volodymyr Zelenskyy said Friday, he heard from several European Union leaders at the EU summit that they were ready to provide aircraft, hinting at what would be one of the biggest shifts yet in Western support for Ukraine. However, Poland's President Andrzej Duda expressed doubt Saturday about whether his country would be able to supply Ukraine with the fighter jets Zelenskyy says are needed to win the war with Russia. Speaking exclusively to BBC, Duda said sending F-16 aircraft would be a "very serious decision" that is "not easy to take." VOA's Eastern European Division Chief Myroslava Gongadze in Kyiv, Ukraine, VOA's National Security Correspondent Jeff Seldin in Washington, and Ani Chkhikvadze of VOA Georgian Service contributed to this report. Some information came from The Associated Press and Reuters.