Andrei Pungovschi/Bloomberg via Getty Images(NEW YORK) -- More than six months after Russian President Vladimir Putin launched an invasion into neighboring Ukraine, the two countries are engaged in a struggle for control of areas throughout eastern and southern Ukraine. Ukrainian President Volodymyr Zelenskyy, whose forces began an offensive in August, has vowed to take back all Russian-occupied territory. But Putin in September announced a mobilization of reservists, which is expected to call up as many as 300,000 additional troops. Here's how the news is developing. All times Eastern: Dec 09, 12:10 PM EST US, Russian diplomats meet in Istanbul A senior U.S. official met with a Russian delegation in Istanbul on Friday to discuss "a narrow set of bilateral issues," according to a spokesperson from the State Department. Citing a hesitancy to discuss "private diplomatic discussions," the spokesperson declined to provide additional detail, but other sources say the agenda was focused on embassy staffing levels, visas and related matters. A spokesperson added that the war in Ukraine was not discussed, nor was Paul Whelan's case. The meeting was initially reported by Russian News Agency TASS. Dec 09, 12:05 PM EST Treasury sanctions 4 Russians for carrying out human rights abuses The U.S. Department of Treasury issued sanctions against four Russians accused of forcibly seizing personal data and conducting interrogations and searches against Ukrainian citizens to determine if they have any connections to the Ukrainian government or military. There are also allegations that deportations, disappearances and torture have also been carried out. Two of those sanctioned "oversaw the filtration of city government officials and other civilians from Mariupol, Ukraine, including through the filtration center in Manhush, Ukraine. Witnesses have reported insufficient food supplies, overcrowded cells, and beatings at the Manhush filtration center. One witness overheard Russia's soldiers discussing shooting people who underwent filtration at Manhush," according to a press release from the Treasury. The Treasury is also sanctioning members of Russia's Central Election Commission for overseeing the sham referenda held in Russian-controlled areas of Ukraine in September, during which Ukrainians were forced to vote for annexation. Dec 07, 6:01 PM EST 10 civilians killed in Russian air strike, Zelenskyy says A Russian airstrike that struck Kurakhov, a city in Donetsk Oblast in southeastern Ukraine, has killed 10 people, Ukrainian President Volodymyr Zelenskyy announced on Wednesday. Civilian areas such as a market, gas station, bus station and a residential building were among the targets that were struck, Zelenskyy said. Dec 07, 1:19 PM EST Putin says Russia will not be the first to use nuclear weapons in war with Ukraine Russian President Vladimir Putin warned on Wednesday the threat of nuclear war is increasing but Russia will not be the first to use nuclear weapons. Putin, speaking at Russia's Human Rights Council, said nuclear weapons should act as a deterrent in conflicts, not provoke them. "We consider weapons of mass destruction, nuclear weapons, it is all built around the so-called retaliatory strike. When we are struck, we strike back," Putin said. "I have already said: we don't have our own nuclear weapons, including tactical ones, on the territory of other countries, but the Americans do. Both in Turkey and in a number of other European states ... we haven't done anything yet," Putin said. -ABC News' Will Gretsky Dec 07, 8:56 AM EST President Volodymyr Zelenskyy named Time's 2022 'Person of the Year' Time named Ukrainian President Volodymyr Zelenskyy and the Spirit of Ukraine as the 2022 "Person of the Year." More than a dozen Ukrainians who embodied the spirit of Ukraine were also named: Dr. Iryna Kondratova, who helped mothers give birth during shelling in the hospital basement; Oleg Kutkov, an engineer who laid the groundwork for the essential connectivity; Olga Rudenko, editor-in-chief of the Kyiv Independent; and Levgen Klopotenko, a Kyiv chef who converted his restaurant into a relief canteen. "This year's choice was the most clear-cut in memory. Whether the battle for Ukraine fills one with hope or with fear, the world marched to Volodymyr Zelensky's beat in 2022," Time editor-in-chief Edward Felsenthal said in a statement. Dec 06, 4:22 PM EST Ukrainian special forces were deep in Russia to guide drone, senior Ukrainian official says Ukrainian special forces were deep inside Russian territory and helped guide drones to at least one of the bases hit in Monday's attacks, a senior official from President Volodymyr Zelenskyy's inner-circle confirmed to ABC News. -ABC News' Marcus Moore Dec 06, 2:28 PM EST White House does not have assessment on drone attacks inside Russia The U.S. does not have an assessment on recent drone attacks deep inside Russia, which a person close to Ukrainian President Volodymyr Zelenskyy told ABC News Ukraine is responsible for, White House press secretary Karine Jean-Pierre told reporters Tuesday. "I don't want to speculate about whether Ukraine is responsible for these attacks," Jean-Pierre said. Jean-Pierre also told reporters Russia is to blame for this conflict. -ABC News' Ben Gittleson Dec 06, 11:30 AM EST Russia now out of Iranian-made drones, Western officials say According to Western officials, Russia has run out of Iranian-made drones. Russia had been using the lethal drones, along with missiles, in a wave of aerial bombardments on Ukrainian infrastructure over a period of several weeks. But, the drones have been absent in recent Russian attacks. A western official said the Russians "anticipate a resupply." In light of Ukraine's apparent drone attacks on military airbases deep inside Russia, Western officials said Russia will now be undergoing "a significant amount of soul-searching" over their ability to defend significant military assets deep inside Russia's borders. The official, who characterized the attacks as "an egregious failure of security" said the Russian military's potential had been consistently overestimated by the west. "I no longer think the Russians are ten-feet tall," the official said. -ABC News' Tom Soufi Burridge Dec 06, 10:17 AM EST Ukrainian drone crashes into military airfield in Russia A Ukrainian drone crashed into a military airfield in Russia, setting an oil tanker on fire, according to the governor of Russia's Kursk region. There were no casualties at the Kursk base. This comes a day after drone attacks on two Russian airbases where jets used to bomb Ukraine are housed. No one immediately claimed responsibility. -ABC News' Joe Simonetti Dec 05, 10:36 AM EST Missiles rain on Ukraine after purported drone strikes in Russia A new barrage of missiles strikes was launched against Ukraine on Monday, hitting targets across the country, including the capital city of Kyiv, officials said. Casualties and damage from the attacks were being assessed, Ukrainian officials said. The majority of the missiles were shot down by air defense forces, Ukrainian officials said. Ukrainian air force spokesman Yuriy Ihnat said the Russians launched missiles from the Volgodonsk, Caspian and Black seas. The strikes damaged two infrastructure objects in the Odesa region, leaving the area without electricity and running water, officials said. One person was hospitalized, according to Ukrainian officials. Odesa Mayor Gennadiy Trukhanov said a missile hit a substation that supplies the city of Belvaevska's pumping station with electricity. According to the office of Ukrainian President Volodymyr Zelenskyy, missile strikes in the Zaporizhzhia region killed two people and injured three others, including a toddler, in the village of Novosofiyivka. Explosion were also heard in Cherkasy, Kharkiv, Dnipropetrovsk, Vinnytsia, Khmelnytskyi, Kherson and Cherkasy, officials said. The