A surge in cross-border assaults on Russia and drone strikes within the country poses a potential for escalation in the Ukraine war, and the US is monitoring it "very, very carefully," according to US Joint Chiefs of Staff Chairman Gen. Mark Milley.

When questioned if the latest drone strikes on Moscow and the bombing of the Belgorod region risked worsening the conflict, Milley responded that there was "always risk".

The Ukrainian armed forces launched a large-scale offensive in five sectors of the South Donetsk area yesterday, according to the Russian Defense Ministry Spokesperson Lt. Gen. Igor Konashenkov.

The Ukrainian armed forces lost more than 250 personnel, 16 tanks, three infantry combat vehicles, and 21 armored fighting vehicles in the South Donetsk direction after the Russian military repelled a large-scale onslaught, according to Konashenkov.

Earlier on Sunday, the Russian Defense Ministry said an artillery strike dispersed a Ukrainian group that attempted to carry out an operation in western Russia near the town of Novaya Tavolzhanka.

Last Thursday, the Ministry also said that Russian troops warded off three Ukrainian cross-border attacks near Shebekino in Belgorod. According to reports, a dormitory was set on fire and one administrative building was damaged in the attacks.  

On the subject of Ukraine's impending counteroffensive against Russia, Milley noted that the armed forces of Ukraine are "very well prepared," but it was too early to expect the outcome.

The US and its Western allies have sent ample amounts of arms to Ukraine to prepare it for its alleged counteroffensive against Russia.

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Last month, the general claimed that the risk of the United States running low on munitions due to significant military aid packages provided to Ukraine amid the war with Russia is “relatively low".

Milley pointed out that the US Secretary of Defense, Lloyd Austin, will carefully look at the munitions issue "to make sure that we don't drop below levels that become moderate, significant, high risk."