Ukrainian troops are achieving "tangible" results against Russian forces in the hotspot northeastern Kharkiv region but the frontline situation is "extremely difficult" elsewhere, President Volodymyr Zelensky said on Tuesday.
Russia launched a fresh assault on Kharkiv on May 10 and has since captured several small settlements in its biggest advance in 18 months.
Moscow on Tuesday also began nuclear weapons drills close to Ukraine in what it said was a response to Western "threats", after Kyiv appealed to allies to down Russian missiles from their own territory.
"In the Kharkiv region, our forces are destroying the occupier, the results are tangible," Zelensky said in his evening address.
But he warned the situation on the eastern front near the cities of Pokrovsk, Kramatorsk and Kurakhove remained "extremely difficult".
"Most of the battles are going on there now," he said.
The Russian official appointed by Moscow as governor of the Kharkiv region said Tuesday that his country's forces controlled nearly half of Vovchansk, a town near the border at the epicentre of fighting.
"Our guys control about 40 percent of the city. They have cut deep into the defence and knocked out the enemy as far as they could," said Vitaly Ganchev.
"The northern part of the city has already been completely liberated," he told Russian state television.
A Ukrainian military spokesman told state media that fighting in the border territories "remains difficult and is changing dynamically".
But he also said the number of bouts with Russian forces had decreased.
Zelensky warned last week that the Russian offensive in Kharkiv might be only a "first wave" and that Russian troops could be aiming for Kharkiv city, Ukraine's second largest.
'Delay costs lives'
Ukraine is struggling to fend off Moscow's forces during the third year of the invasion, pleading for more weapons for its outgunned and outnumbered troops as Russian strikes cripple its energy infrastructure.
Ukrainian Foreign Minister Dmytro Kuleba on Tuesday said allies could shoot down Russian missiles from their own territory, in an apparent appeal stemming from the country's critical lack of air defence systems.
"There is no legal, security or moral argument that stands in the way of our partners shooting down Russian missiles over the territory of Ukraine from their territory," Kuleba said during a press conference with his German counterpart Annalena Baerbock.
"If you don't want to do it, then just provide us with all the means necessary for this. We will deploy them on the territory of Ukraine and intercept these missiles ourselves," he said.
Baerbock added that delaying aid to Ukraine also put Western countries' security at risk.
"Every hesitation and every delay in supporting Ukraine costs the lives of innocent people. And every hesitation in supporting Ukraine also jeopardises our own security," she said.
Arriving in Kyiv by train for her eighth visit since Russia invaded in February 2022, Baerbock had acknowledged the situation on the front had "dramatically deteriorated", citing Russian air attacks and its major ground offensive in Kharkiv.
But she also voiced confidence that Ukrainian forces would achieve their goals and that the West would keep delivering aid.
In a rebuke to Baerbock, the Kremlin said that even if supplies of Western weapons to Ukraine picked up, more deliveries would not change Russia's dominant position on the battlefield.
"It will still not allow the Ukrainian armed forces to somehow change the dynamics on the fronts," spokesman Dmitry Peskov told reporters.
Drone barrage
Moscow had already announced earlier this month that its forces stationed near Ukraine would conduct the tactical nuclear weapons drills, without giving a clear date.
The defence ministry said Tuesday that the drills would test the "readiness" of its "non-strategic nuclear weapons... to ensure the territorial integrity and sovereignty of the Russian state".
They come in "response to provocative statements and threats by certain Western officials", the ministry added.
Zelensky has repeatedly called on Ukraine's allies to provide at least seven more air defence systems, including at least two to protect the Kharkiv region.
Just before Baerbock arrived, the Ukrainian air force said it had intercepted 28 of 29 Iranian-designed attack drones launched by Russian forces overnight over southern and eastern regions of the country.
