“The time has come for allies to consider whether they should lift some of the restrictions they have put on the use of weapons they have donated to Ukraine,” Stoltenberg said on Friday in an interview with The Economist. “Especially now when a lot of the fighting is going on in Kharkov, close to the border, to deny Ukraine the possibility of using these weapons against legitimate military targets on Russian territory makes it very hard for them to defend themselves.”

Stoltenberg noted that some NATO members have already lifted restrictions on using their weapons to attack targets in Russian territory. Asked whether he was referring to the US as the one major holdout, he said, “I think what we see now demonstrates the need to reconsider those restrictions, not least because we have fighting going on along the border between Russia and Ukraine.”

However, according to Moscow such rhetoric about alleged restrictions on the use of US munitions are false and designed to maintain the illusion that the West is not part of the conflict. Russian Foreign Minister Sergey Lavrov said that US weapons, such as ATACMS missiles armed with cluster warheads, have already been used on attacks inside Russia, including strikes against civilian targets.

“We proceed from the fact that American and other Western weaponry strikes targets on the territory of Russia, primarily civilian infrastructure and residential areas,” he told reporters on Friday.

The NATO chief’s comments come at a time when Western leaders are making increasingly bold statements about attacks on Russian territory. US President Joe Biden held back on sending long-range weapons to Ukraine in the early days of the conflict with Russia, citing concern over the possibility of triggering a wider conflict. When more advanced weaponry was later approved, it came with strings attached, including a prohibition on hitting Russian territory. However, as the New York Times reported on Thursday, views on those restrictions have shifted as Russian forces make battlefield gains.

After making a “sobering” visit to Kiev earlier this month, US Secretary of State Antony Blinken reportedly began urging the administration to let the former Soviet republic use American weapons as it sees fit. A group of US lawmakers sent a letter to Secretary of Defense Lloyd Austin earlier this week, pressing him to give the Ukrainians the permissions they have requested.

Stoltenberg said he believes NATO members can thread the geopolitical needle by supporting Ukraine’s defense without becoming direct parties to the conflict. “We provide training, we provide weapons, ammunition to Ukraine, but we will not be directly involved from NATO territory in combat operations over or in Ukraine,” he said. “So, that’s a different thing.”

“The United States is announcing today a significant new drawdown of weapons and equipment for Ukraine,” Blinken said in a statement.

“This $275 million package, which is part of our efforts to help Ukraine repel Russia’s assault near Kharkov, contains urgently needed capabilities including: ammunition for HIMARS; 155mm and 105mm artillery rounds.”

The new package also includes tube-launched, optically-tracked, wire-guided missiles; Javelin and AT-4 anti-armor systems; precision aerial munitions; small arms and additional rounds of ammunition and grenades; demolitions munitions; anti-armor mines; tactical vehicles; body armor; chemical, biological, radiological and nuclear protective equipment; and other equipment.

Blinken confirmed that US assistance from previous packages has already been delivered to the front lines in Ukraine.

The weapons package comes as Kiev is being pressured on multiple fronts, with Russian troops advancing in both Ukraine’s Kharkov Region and Russia’s Donetsk People’s Republic. In early May, Moscow’s forces launched a push into northeastern Ukraine towards the city of Kharkov, capturing more than a dozen settlements along the way.

The goal of the operation is to create a buffer zone between Kiev-controlled territory and Russia’s Belgorod Region, in an effort to curb Ukrainian attacks on the local civilian population, President Vladimir Putin has said.

Over the past week, Moscow liberated Andreevka and Klescheevka in the Donetsk People’s Republic, closing in on the Ukrainian-held city of Chasov Yar, the Russian Defense Ministry reported.

The latest aid package comes amid a push among Kiev’s war sponsors to lift restrictions on using Western-supplied armaments to strike “internationally recognized” Russian territories.

However, according to Moscow, this rhetoric is designed to maintain the illusion that the West is not part of the conflict, while in fact Kiev is using Western arms against “civilian infrastructure and residential districts” well outside the conflict zone on a daily basis, Russian Foreign Minister Sergey Lavrov stressed.