According to senior US military officials, Ukraine confronts a difficult fight in its ongoing counteroffensive against Russian forces, and the campaign to recapture territory will likely be "expensive."
The US assessment of Kyiv's counteroffensive came as Chechen fighters said they had deployed to Russia's Belgorod region bordering Ukraine to prevent attacks by pro-Ukraine Russian partisan groups, and Ukrainian military officials reported front-line advances in multiple locations on Thursday.
"Ukraine has begun its assault and is making solid progress. This is an extremely challenging battle. Thursday at NATO headquarters in Brussels, US Army General Mark Milley, chairman of the Joint Chiefs of Staff, described the conflict as "extremely violent" and "likely to take a significant amount of time at a high cost.
Milley, speaking after a meeting of the US-led Contact Group of approximately 50 countries that provide military assistance to Ukraine, stated that it was far too early "to make any estimates" regarding the duration of the Ukrainian counteroffensive.
US Defense Secretary Lloyd Austin stated at the meeting that Kyiv required short-term and long-term support as the conflict was a "marathon, not a sprint" and that Ukraine required even more weapons.
Despite initial losses inflicted by Russia, according to Austin, Ukraine still possessed ample ordnance to conduct its counteroffensive.
Moscow has shown video footage of captured German Leopard tanks and American-donated Bradley fighting vehicles, which it claims were seized at the beginning of Ukraine's offensive to reclaim territory from Russia.
Austin stated regarding the video clips, "I believe the Russians have shown us the same five vehicles approximately 1,000 times from ten different angles." "However, the Ukrainians still possess considerable combat capability and power," he said.
"This is a war, so we know that both sides will suffer battle damage," Austin said, adding that Kyiv's capacity to repair damaged equipment was more crucial.
"As expected, this will continue to be a difficult battle, and I believe that the side that performs the best in terms of endurance will likely emerge victorious," he added.
The Ukrainian counteroffensive is in its infancy, and according to military specialists, the decisive battles are yet to come. Ukraine has recaptured at least seven settlements and 100 square kilometers (38 square miles) of territory during two significant offensives in the south thus far, according to Ukraine's Brigadier General Oleksii Hromov on Thursday.
"We are prepared to continue fighting with our bare hands to liberate our territory," he said. Ukraine's army on the southern front advanced up to 7 kilometers (4.4 miles) along the Mokry Yali and up to 3 kilometers (1.8 miles) near Mala Tokmachka, according to Ukrainian military officials.
Valeriy Shershen, a spokesman for the Tavria military sector in southern Ukraine, told Ukrainian television, "Our units and troops are advancing in the face of intense fighting and enemy aviation and artillery superiority." Also reported were advances in the east surrounding the ruined city of Bakhmut, which Moscow captured last month.
However, the true test of Ukraine's offensive is yet to come, as Ukrainian soldiers have yet to reach the most formidable Russian defensive positions, which are located behind the front line. Kyiv is believed to have prepared an attack force consisting of approximately 12 brigades containing thousands of soldiers each, the majority of which are equipped with recently arrived Western armored vehicles.
Institute for the Study of War (ISW), a thinking center based in Washington, DC, stated on Friday that current operations by Ukrainian forces are "setting the conditions for broader Ukrainian counteroffensive objectives that are not immediately apparent."
According to the ISW, the current combat "represents the initial phase of an ongoing counteroffensive."
This week, Russian President Vladimir Putin insisted that Russian forces were inflicting ten times more casualties on Ukrainians than Ukrainian forces were suffering and that Kyiv's offensive had failed.
On Thursday, Ramzan Kadyrov, the leader of Chechnya, stated that fighters from the "Zapad-Akhmat" battalion had been deployed near the site of a May cross-border assault by Russian-speaking pro-Ukrainian fighters.
"Residents of the territories adjacent to the Ukraine frontier can sleep soundly... Whoever violates our borders will be met with a swift response," Kadyrov said in a post on the messaging app Telegram.