Russian forces have shot down 31 drones during a concerted Ukrainian night-time attack on border regions, the Russian defence ministry says, as uncertainty grew over Ukraine's future access to weapons and ammunition from its allies.
The drone attack appeared to be Ukraine's largest single cross-border drone assault reported by Russia since the Kremlin launched its invasion 20 months ago.
There were no immediate reports of damage or casualties.
Ukraine is pressing on with the slow-moving counteroffensive it launched three months ago to expel Russian invaders although mounting concerns about replenishing its military stocks and cracks in support among its allies cast a cloud over the effort.
Admiral Rob Bauer, the head of NATO’s military committee, sounded the alarm about depleted stockpiles.
"The bottom of the barrel is now visible," Bauer said of weapons systems and ammunition supplies.
With the war of attrition likely continuing through the northern hemisphere winter into next year, Bauer urged the defence industry to boost production "at a much higher tempo. And we need large volumes,” he told the Warsaw Security Forum, an annual two-day conference that continued on Wednesday.
The Russian defence ministry did not provide any evidence for its claims about intercepting Ukrainian drones.
It also said Russian aircraft thwarted a Ukrainian attempt to deploy a group of soldiers by sea to the western side of Russian-occupied Crimea.
The force attempted to land on Cape Tarkhankut using a high-speed boat and three jet skis, the ministry said.
The Russian claims could not be independently verified, and Ukrainian officials made no immediate comment.
The Crimean Peninsula, which Russia annexed from Ukraine in 2014, has been a frequent target of Ukrainian attacks.
The region has been the key hub supporting the invasion.
Concerns over the resupply of Ukraine's armed forces have deepened amid political turmoil in the United States and the unprecedented ouster pn Tuesday of House Speaker Kevin McCarthy.
The US is by far Ukraine’s largest military supplier but a faction in the House Republican majority, and many of the party's voters, oppose sending more military aid to Ukraine.
The Pentagon has warned Congress that it is running low on money to replace weapons the US has sent to Ukraine.
Mykhailo Podolyak, an adviser to Ukrainian President Volodymyr Zelenskiy, publicly questioned the motives of what he called "Western conservative elites".
"Why are you so insistently against... destroying the Russian army, which has been terrifying," he wrote on social media platform X.
The funding concerns prompted US President Joe Biden to hold a phone call on Tuesday with key allies in Europe, as well as the leaders of Canada and Japan, to co-ordinate support for Ukraine.
The call was held three days after Biden signed legislation hastily sent to him by Congress that kept the federal government funded but left off billions in funding for Ukraine’s war effort that the White House had vigorously backed.
Meanwhile on Wednesday, sirens blared across Russia and television stations briefly interrupted regular broadcasts to air emergency warnings as part of drills to test the readiness of the country’s emergency agencies.
Russian media said the drills, which started the previous day, envisioned the increasing danger of a conflict between nuclear powers.
The exercise was meant to simulate a situation in which 70 per cent of housing and all vital infrastructure are destroyed and wide areas are contaminated by radioactive fallout.
The drills follow a series of warnings from Russian officials that foreign support for Ukraine has increased the threat of a direct military conflict between Russia and the NATO military alliance.
The US federal government on Wednesday is also testing its Emergency Alert System, designed to allow the president to speak to the public within 10 minutes during an emergency via outlets such as radio and television.
It also will send test messages to mobile phone customers in the United States, according to the Federal Emergency Management Agency.
