KYIV, Ukraine (AP) -- The Ukrainian military said Monday that it recaptured strategic gas and oil drilling platforms from Russia in the Black Sea and claimed gains in occupied areas near Bakhmut, a city in eastern Ukraine left in ruins after the war's longest and deadliest fighting.
The recapture of the so-called Boyko Towers platforms provides an energy source and takes back an asset that Russia seized in 2015 and used to launch helicopters, Ukraine's Ministry of Defense said.
"Russia has been deprived of the ability to fully control the waters of the Black Sea, and this makes Ukraine many steps closer to regaining Crimea," the Main Intelligence Directorate said.
The Russian Defense Ministry didn't make any immediate comment on the Ukrainian claim, but it has previously reported that Russian warplanes destroyed several Ukrainian speedboats in the area.
Russian military bloggers posted that the platforms had been uninhabited for more than a year and a Ukrainian operation to briefly land troops there last month wasn't followed by a lasting military presence and came at a heavy cost for Ukraine, a claim that couldn't be independently verified.
Ukrainian President Volodymyr Zelenskyy has vowed to do all he can to bring back Crimea, which Russia annexed from Ukraine in 2014, and has urged international allies to support the effort.
Ukraine's reported battlefront gains, which could not be independently confirmed, came ahead of a meeting expected in coming days between Russian President Vladimir Putin and North Korean leader Kim Jong Un, which could include discussions of North Korea providing arms to restock Russia's dwindling arsenal.
In other developments, German Foreign Minister Annalena Baerbock made an unannounced visit to Kyiv, Ukraine's capital. She promised support for Ukraine's path toward European Union membership while calling for additional reforms in the country.
"With enormous courage and determination, Ukraine is also defending the freedom of all of us," Baerbock said in a statement released by her ministry. "In the same way that Ukraine stands up for us, it can also count on us."
Baerbock also pledged continued military, economic, and humanitarian support for the country and said the 22 billion euros ($23.6 million) provided so far now made Germany second to the U.S. in terms of total support.
Baerbock said that while Ukraine had already made good progress reforming the judiciary and the media, it still had "some way to go" in combating corruption.
In fighting, Ukrainian forces liberated part of the Donetsk province town of Optyne and advanced on the towns of Klishchiivka and Andriivka south of Bakhmut, Deputy Defense Minister Hanna Malyar said.
Combat has persisted on the outskirts of Bakhmut since Ukrainian troops pulled out of the city in May. Ukraine is trying to gain the high ground in Klishchiivka, to establish artillery control over Bakhmut.
In southern Ukraine's Zaporizhzhia province, Ukraine's primary counteroffensive forces were inching closer to overcoming Russian fortifications and dense minefields to take Tokmak, a critical logistics hub for Russian forces and a vital railway junction, Malyar said.
Ukrainian forces liberated Robotyne, a town in the same province, last month.
Russian forces also attacked the Dnipropetrovsk province city of Kryvyi Rih, Zelenskyy's birthplace, with drones overnight, Ukrainian authorities said. There were no immediate reports of casualties or damage.
The retaking of the Black Sea platforms follows the U.K. Ministry of Defense reporting naval and air force skirmishes at sea two weeks ago.
Ukraine has struck several Russian-controlled platforms in fighting during the war, and troops from both countries have occupied them periodically, the U.K. said in a military update on the war. Along with drilling, the platforms can be used to land helicopters, as deployment bases and to position long-range missile systems.
Pro-Russia occupation authorities seized the platforms operated by the Chernomorneftegaz company following the annexation of Crimea, which most of the world regarded as illegal.
The U.K. Foreign Office on Monday also cited intelligence showing that the Russian military allegedly targeted a Liberian-flagged cargo ship berthed in the Black Sea port of Odesa with multiple missiles on Aug. 24, an attack that followed Moscow's withdrawal in July from a landmark deal allowing Ukraine to export grain safely through the Black Sea. The Foreign Office said the missiles fired at Odesa were downed by Ukrainian forces.
"Putin is trying to win a war he will not win, and these attacks show just how desperate he is," U.K. Foreign Secretary James Cleverly said. "In targeting cargo ships and Ukrainian infrastructure, Russia is hurting the rest of the world."
After Russia's full-scale invasion of Ukraine more than 18 months ago, Putin illegally annexed four provinces in September 2022: Donetsk, Kherson, Luhansk and Zaporizhzhia. Voting for Kremlin-installed legislatures began in the occupied areas last week as Russian authorities attempt to tighten their grip on territories that Moscow still does not fully control.
Russia's Central Election Commission said Monday that the country's ruling party, United Russia, placed first in the four Ukrainian regions and in Crimea.