Italy's Prime Minister Giorgia Meloni reiterated Sunday her opposition to the use of weapons supplied to Ukraine on Russia soil, after the NATO chief reportedly suggested letting Kyiv strike targets beyond its border.

According to Italian media reports, NATO Secretary General Jens Stoltenberg told the British weekly The Economist that Ukraine's allies should consider letting it use NATO-supplied weapons to hit targets in Russia, rather than restricting use to Ukrainian territory. 

"I don't know why Stoltenberg said such a thing, I think we have to be very careful," Meloni told Italian television while adding that "I agree that NATO must remain firm, not give the signal that it is giving in".

Ukraine regularly launches strikes across the border into Russia, particularly into the Belgorod region, a tactic it views as fair retaliation in the fighting since Moscow launched its invasion in February 2022.

According to The Economist, Ukraine so far has been using home-produced drones for its strikes Russia.

"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 in the Economist interview published Friday.

"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," he said.

The comments sparked an outcry from officials in Italy, which is providing military aid to Ukraine but fears that the conflict could spread.

Speaking at an election rally in Naples, Matteo Salvini, deputy prime minister and leader of the anti-migrant League party, slammed Stoltenberg's remarks, saying: "This gentleman either asks for forgiveness, rectifies his remarks or resigns." 

Foreign Minister Antonio Tajani said that "the military equipment sent by Italy" must "be used inside Ukraine". 

On Thursday, before Stoltenberg's interview, Moscow denounced mounting calls from Washington for Ukraine to be allowed to fire donated American weaponry into Russia.

"We know that among US Senators and Congressmen, there are very many hotheads who consider it their duty to keep pouring oil on the fire," Kremlin spokesman Dmitry Peskov said in a video posted by Russian journalist Pavel Zarubin.

Peskov condemned the "an absolutely irresponsible position" that could be "dangerous in its consequences".