The hacking assault underscored the continuing threat to Ukraine’s statehood, as political infighting between Democrats and Republicans in Washington risks cutting off aid to Ukraine from its most important ally.
On Tuesday, the White House said that Russian President Vladimir Putin remains intent on conquering Ukraine and subjugating its people even though Russia has incurred major human costs as Moscow’s troops seek to advance further Ukrainian-held territory.
Russia’s military has incurred more than 13,000 casualties along the Avdiivka-Novopavlivka axis in eastern Ukraine since launching an offensive there in October, and ha lost more than 220 combat vehicles, according to newly downgraded intelligence shared on Tuesday by the National Security Council. The vehicle losses equate to six maneuver battalions worth of equipment.
“Russia seems to believe that a military deadlock through the winter will drain Western support for Ukraine and ultimately give Russia the advantage despite Russian losses and persistent shortages of trained personnel, munitions, and equipment,” Council spokeswoman Adrienne Watson said in a statement.
“Russia is determined to press forward with its offensive despite its losses,” Watson said. “It is more critical now than ever that we maintain our support for Ukraine so they can continue to hold the line and regain their territory.”
Ahead of his visits to Congress and the White House, Zelensky laid out the stakes in a series of posts on the social media platform X, formerly Twitter, summarizing a speech he made Monday at the National Defense University in Washington in which he said Ukraine is fighting to “stop Russia right at the start of its global war on freedom.”
“You can rely on Ukraine, and we expect to be able to rely on the U.S.,” Zelensky said. “When the free world hesitates, dictatorships rejoice, and their most dangerous ambitions ripen.”
Addressing members of the military in the audience, he told them they understood “what it means for a soldier to wait for munition, for weeks, months, without knowing it will come at all. When instead of moving forward you’re just watching, waiting for ammo or equipment, while your enemy is satisfied and preparing assaults.”
Zelensky’s blunt remarks flicked at Ukrainian frustrations over this year’s stalled counteroffensive, which was slow to start in part because Ukraine insisted it needed additional weapons and training from its Western supporters, especially the United States, to successfully push back occupying Russian forces.
In the meantime, Russia significantly built up formidable defensive positions across southern and eastern Ukraine, creating treacherous battlefield conditions including vast minefields, which led to significant losses of Ukrainian equipment and troops.
The war in Ukraine has combined elements of World War I-style trench warfare with 21st century high-tech weaponry, including swarms of explosive drones, many controlled using live-feeds over the internet. Russia has repeatedly sought to disrupt internet service in Ukraine, forcing the country’s military to rely heavily on Starlink, the satellite internet system operated by Elon Musk’s company, SpaceX.
The massive hacking attack on Tuesday morning, hours before Zelensky was to begin his meetings in Washington, hit Ukraine’s regular network.
Kyivstar, the country’s largest mobile telephone provider, said that entirety of its network — totaling more than 24 million subscribers — had been brought down.
Among those affected by the hack was Olha Stefanishyna, Ukraine’s deputy prime minister for European and Euro-Atlantic integration, who was in Brussels on Tuesday rallying support for the E.U. to open accession talks with Ukraine.
“Unfortunately, this morning Kyivstar became the target of the most powerful hacker attack, as a result of which communication and internet access services were temporarily unavailable,” Kyivstar’s executive director Oleksandr Komarov said in a video posted on social media.
Users throughout Ukraine and abroad were left without cellphone service, and found they could not switch to other carriers since the network’s roaming services were also down, Ukrainian media reported.
“The war with Russia has many dimensions and one of them is in cyberspace,” Komarov said. He did not provide details of how the attack was carried out, or precisely when it took place. Kyivstar has “engaged representatives of law enforcement agencies and special state services … to find out the circumstances and consequences” of the hack,” he said.
Ukraine’s intelligence service, the SBU, said that it was investigating the possibility “that the special services of the Russian Federation may be behind this hacker attack.”
In a press statement, the SBU said that it had opened eight criminal investigations into the incident, including charges of treason, sabotage and “planning, preparation, unleashing and waging an aggressive war.”
Other Ukrainian companies reported that their systems were also targeted, though it was not clear if these incidents were connected to the hack of Kyivstar.
Oleg Gorokhovsky, the head of Monobank, a Ukrainian online financial services provider, said that his company had overcome a “massive” distributed denial-of-service, or DDOS, attack, in which an attacker tries to crash a network by overwhelming it with a surge in traffic.
Zelensky’s comments at the National Defense University also reflected his growing frustration over hesitance among some U.S. lawmakers to approve additional aid for Ukraine, which Republicans tied into a package with controversial border control measures hoping it would win additional conservative support. Instead, further disagreements have stalled any progress, and last week Zelensky abruptly canceled plans to attend a briefing for U.S. senators.
The meeting in the Senate soon turned into a shouting match.
There is now little optimism in Kyiv or among Ukraine’s supporters in Washington that any further aid will be approved this calendar year — but Ukrainian officials hope Zelensky can help persuade U.S. lawmakers to commit to further assistance in January.
Meanwhile, the European Union is trying to push through additional emergency financial support for Kyiv and to begin formal negotiations for the country’s accession to the 27-nation bloc. But E.U. officials in Brussels are facing a roadblock, with Hungary threatening to veto any such plans.
Video footage this weekend showed Zelensky and Hungarian Prime Minister Viktor Orban in heated discussion on the sidelines of the inauguration of Argentina’s new president, Javier Milei. Orban has maintained a close relationship with Russian President Vladimir Putin and repeatedly has questioned Western support for Kyiv in the war against Moscow’s invading forces.
The drama over the West’s commitment to backing Ukraine has ramped up anxiety in Kyiv, where politicians and the general public recognize that decreased assistance could pose an immediate, existential threat. Russian forces now occupy roughly one-fifth of Ukraine’s sovereign territory, including Crimea, which Moscow invaded and annexed illegally in 2014.
Ukraine relies on U.S. support for a wide range of weaponry, including munitions for air defense systems that protect civilians in cities far from the front line. Russia continues to launch regular missile and drone attacks on cities across Ukraine, including Kyiv.
There are also fears that if Ukraine does not have the weapons it needs to advance on the front or even defend its current positions, it could be forced to negotiate and surrender some of the territory Russia has seized — a scenario that until now Zelensky has insisted will not happen and would only embolden Russia to continue its assaults on the international order.
Putin, in violation of international law, has proclaimed the annexation of four Ukrainian territories — Luhansk, Donetsk, Zaporizhzhia and Kherson, despite much of that territory still being in Ukrainian control. Russia has said it intends to carry out its March presidential election in the occupied territories of Ukraine.
If Western aid does not come through, there is little backstop available.
On Tuesday, Ukrainian lawmaker Yaroslav Zhelzniak posted a screenshot of draft Ukrainian legislation for a daily prayer time for victory against Russia and joked: “I understand that the coalition finally has a plan B in case the military and financial assistance is not voted on in time?”
Ryan reported from Washington. Emily Rauhala in Brussels and Serhiy Morgunov in Kyiv contributed to this report.
