By SUSIE BLANN
KYIV, Ukraine (AP) -- Ukrainian forces were making a major effort to end months of a battlefield stalemate and punch through Russian defensive lines in southeast Ukraine for a second day, with Russian officials saying on Monday that Moscow's forces have foiled at least one assault.
Kyiv authorities said their forces were indeed increasing offensive operations and making gains, but suggested some of the Russian announcements were misinformation as speculation grows about a widely anticipated counteroffensive after more than 15 months of war.
Vladimir Rogov, an official in the Russia-backed administration of Ukraine's partly occupied Zaporizhzhia province, said fighting resumed on its border with the eastern Donetsk province on Monday after Russian defenses beat back a Ukrainian advance the previous day.
"The enemy threw an even bigger force into the attack than yesterday (Sunday)," and the new attempt to break through the front line was "more large-scale and organized," Rogov said, adding: "A battle is underway."
Rogov interpreted the Ukrainian military movements as part of an effort to reach the Sea of Azov coast and sever the land corridor to the Crimean Peninsula, which Moscow annexed in 2014. Analysts have long viewed that strategy as likely because it would cut the Russian forces in two and severely strain supplies to Crimea, which has served as a key Russian military hub in the war that started Feb. 24, 2022.
Rogov's comments came after Moscow also said that its forces thwarted large Ukrainian attacks in Donetsk province, near its border with the Zaporizhzhia province.
Ukrainian Deputy Defense Minister Hanna Malyar said the Ukrainian military has scored gains.
"Despite fierce resistance and attempts of the enemy to hold the occupied lines and positions, our units moved forward in several directions during the fighting," she said.
Malyar drew no distinctions between phases of the war, insisting that Ukraine's defense against Russia's invasion "contains everything, including counter-offensive actions." She acknowledged that Kyiv's forces "in some areas ... are shifting to offensive operations."
Retired British Gen. Richard Barrons, co-chair of the U.K.-based strategic consulting firm Universal Defence & Security Solutions, said Ukraine was "clearly in the preliminary phase" of its counteroffensive.
"The focus will be on the tanks and artillery, and infantry -- that's the most visible tip of the spear," he told The Associated Press, noting that the counteroffensive will also include politics, diplomacy, information and cyber warfare.
A Ukrainian Defense Ministry video showed soldiers putting a finger to their lips in a sign to keep quiet. "Plans love silence," it said on the screen. "There will be no announcement of the start."
Zaporizhzhia and Donetsk are two of the four provinces that President Vladimir Putin claimed as Russian territory last fall and which Moscow partially controls.
Russia's Defense Ministry said it had pushed back a "large-scale" assault Sunday at five places in Donetsk province. The announcement couldn't be independently verified, and while Ukrainian officials reported fighting in that area, they didn't confirm a retreat.
Russian Defense Ministry spokesman Igor Konashenkov said in an unusual overnight video that 250 Ukrainian personnel were killed in the fighting in Donetsk province, and 16 Ukrainian tanks, three infantry fighting vehicles and 21 armored combat vehicles were destroyed.
"The enemy's goal was to break through our defenses in the most vulnerable, in its opinion, sector of the front," Konashenkov said. "The enemy did not achieve its tasks. It had no success."
Ukrainian officials have said for months that a spring campaign with advanced weapons supplied by Western allies to reclaim territory seized by Russia during the war was planned, but they have kept quiet about when, how and where it might start, or whether it had already been launched.
Recent military activity, including drone attacks on Moscow, cross-border raids into Russia and sabotage and drone attacks on infrastructure behind Russian lines, has unnerved Russians. Analysts say those actions may represent the start of the counteroffensive.
After months of a battlefield stalemate, with neither side making significant gains and suffering losses of personnel and weapons, Ukraine could launch simultaneous pushes in different areas of the front line that stretches for nearly 700 miles, analysts say.