US Secretary of State Antony Blinken said on Tuesday that American military aid on its way to Ukraine would make a “real difference” on the battlefield. The comments came as the top diplomat made an unannounced visit to Kyiv to reassure its ally facing a fierce new Russian offensive. Moscow’s troops have captured around 100 to 125 square kilometers in the Kharkiv region in recent days. This includes at least seven villages, according to open-source monitoring analysts, with thousands of civilians fleeing the fighting. Kremlin forces have also been making a concerted push in the east seeking to drive deeper into partly-occupied Donetsk, a region just inside the Ukrainian border in Donetsk. Ukrainian general staff said in a report Russia launched 24 assaults on Pokrovsk. Analysts have called this moment one of the most dangerous for Ukraine since Russia"s full-scale invasion in February 2022. President Volodymyr Zelensky asked on Tuesday for more air defense systems to protect civilians under Russian fire in the northeast. “We know this is a challenging time,” Blinken said in the Ukrainian capital where he met with Zelensky. But American military aid is “going to make a real difference against the ongoing Russian aggression on the battlefield," he added. The visit comes less than a month after Congress approved a long-delayed foreign assistance package that sets aside €55.5 billion in aid for Ukraine. Most of this will go toward replenishing badly depleted artillery and air defense systems. Blinken said aid “is now on the way", with some already arriving in Ukraine. Moscow’s renewed offensive in the northeast region of Kharkiv is the most significant border incursion since the early days of the war. It comes after months of the roughly 1,000-kilometer front line barely budging with more than 7,500 civilians evacuated from the area, according to authorities. At the same time, the Kremlin’s forces are expanding their push to the northern border regions of Sumy and Chernihiv, Ukrainian officials say. Kyiv"s outgunned and outnumbered soldiers are struggling to hold them back. Governor of Kharkiv Oblast said troops fought street to street on the outskirts of Vovchansk, which is among the largest towns in the Kharkiv area. Two civilians were killed in the Russian shelling on Tuesday, he said. The UN Human Rights Office said the battles are taking a heavy toll. “We are deeply concerned at the plight of civilians in Ukraine,” said Liz Throssell, spokeswoman for the office of the UN High Commissioner for Human Rights. “In the Kharkiv region, the situation is dire.” Zelenskyy thanked Blinken for the US aid but said more is necessary. This includes two Patriot air defense systems urgently needed to protect Kharkiv. “The people are under attack: civilians, warriors, everybody. They’re under Russian missiles,” he said. Blinken, on his fourth trip to Kyiv since Russian troops rolled over the border, told Ukrainian Prime Minister Denys Shmyhal that the US intends to support Kyiv beyond the war"s end. “The United States is determined, determined to help Ukraine succeed, succeed both in the battlefield victory but also succeed, as we would say, in winning the peace and building the strongest possible Ukraine,” he said. National security adviser Jake Sullivan said the administration is “trying to really accelerate the tempo” of US weapon shipments. But delays in US assistance, particularly since the Israel-Hamas war began and preoccupying top administration officials, have triggered deep concerns in Kyiv and Europe. — Euronews