Ukraine announced it has retaken full control of Lyman, a city within one of the four regions Russian President Vladimir Putin proclaimed were annexed forever by the Kremlin last week, NBC News reports.

"Lyman is cleared fully," Ukrainian President Volodymyr Zelenskyy said Sunday (October 2) morning, hours after Russia's Defense Ministry announced the withdrawal of troops form the city.

“Over the past week, the number of Ukrainian flags in Donbas has increased. There will be even more in a week’s time,” Zelenskyy had previously said during his Saturday (October 1) evening address via NBC News.

Lyman is in the Donetsk region which, along with Luhansk, Kherson and Zaporizhzhia, were among the territories Putin vowed would be recognized as Russian territories as part of the biggest annexation in Europe since World War II last Friday (September 30), Reuters reported.

Putin's announcement came after several previous setbacks during Russia's invasion of Ukraine prior to the neighboring country reclaiming Lyman.

Pro-Russian officials confirmed that Kremlin troops were on the verge of encirclement in Lyman amid Putin's announcement last week, while others believed the battle would've provided an opening for Ukraine to take back the four territories, according to Reuters.

Last month, Putin announced a partial military mobilization of 300,000 reservists and reiterated warnings to Western allies that he was ready to use nuclear weapons in Moscow's ongoing invasion of neighboring Ukraine, during a rare, prerecorded television announcement, Reuters reported.

Putin claimed that Ukraine -- a country he ordered troops to invade earlier this year -- "wants to destroy our country" during the announcement.

"If the territorial integrity of our country is threatened, we will use all available means to protect our people - this is not a bluff," Putin said via Reuters.

Russia's defense minister Sergei Shoigu confirmed that 300,000 reservists with prior military experience would be called up as part of the partial mobilization.

The decision marked Russia's first mobilization since World War II and the biggest escalation since invaded Ukraine in February.

Ukraine and its Western allies said Putin's call for more troops signified that his invasion of the neighboring country was failing.

"Absolutely predictable appeal, which looks more like an attempt to justify their own failure," Ukrainian Presidential Adviser Mykhailo Podolyak told Reuters. "The war is clearly not going according to Russia's scenario."

Allies vowed to continue their support of Ukraine amid Putin's announcement.

Putin announced his country would conduct military operations in Eastern Ukraine during an NBC News translation of a speech addressing the Russian population in Moscow on February 24.

The announcement appeared to serve as the final action ahead of an attack by Putin and the Russian military, which the U.S. and European allies to the neighboring Ukraine have attempted to prevent from taking place through diplomatic discussions.