LONDON / ATHENS

The NATO secretary-general on Friday dismissed an escalation warning by Moscow over Ukrainian strikes inside Russia, saying Ukraine has the right to self-defense, including striking legitimate military targets inside Russia.

"Ukraine must be able to hit back and to defend themselves. This is part of the right for self-defense," Jens Stoltenberg said at the doorstep of the Foreign Ministers Meeting in the Czech capital Prague.

Asked about reports that US President Joe Biden has granted Ukraine secret approval to use US-supplied weapons to strike inside of Russia, the NATO chief said he welcomes that NATO allies are providing support to Ukraine in many different ways, but added that he "will not go into the details about exactly what type of support they are getting."

US permission is intended to help Kyiv better defend against Russian attacks on Kharkiv, Ukraine's second-largest city, the Politico news website reported on Thursday, citing two Biden administration officials, and two people familiar with the matter.

"What I have stated many times is that we need to remember this is a war of aggression. Russia has attacked another country, violated international law, invaded Ukraine, and Ukraine has the right for self-defense and that includes also the right to strike legitimate military targets inside Russia," he noted.

He went on to say that this has become even "more urgent," as Russia just opened a new front on the northeastern border, attacking the Kharkiv region.

Asked about how lifting restrictions on using donated weapons could change the situation on the ground, Stoltenberg said several allies have never been imposed restrictions on the supply they have delivered to Ukraine.

"If you look at the battlefield now, Russia is launching attacks on Ukrainian soil from Russian soil, with artillery with missiles ... and of course, it makes it very hard for Ukraine to defend themselves if they're not allowed to use advanced weapons to repel those attacks," said the NATO chief.

On the recent Ukrainian attack on Russian nuclear radar stations, he said: "I will not go into the details except for saying that of course we all assume that this will be done in a responsible way."

'More, sustained support for Ukraine'

Separately, speaking at a joint news conference with US Secretary Antony Blinken ahead of the meeting, Stoltenberg underlined that one of the hot topics of the summit is ensuring more and sustained support for Ukraine.

"I also proposed a multiyear financial pledge to ensure more accountability and predictability in the support we provide to Ukraine because we need to make sure that Moscow understands that we are prepared for the long haul in our support for Ukraine," he said.

Stoltenberg added that consolidating the alliance’s global partnerships, in particular with Asia-Pacific partners Australia and New Zealand, Japan, and South Korea, and improving its deterrence and capabilities will be also discussed.

Blinken, for his part, praised NATO as the most successful alliance in history and said they are working to further improve the alliance’s deterrence.

Earlier, Stoltenberg also said: "I have proposed that NATO should play a bigger role in the coordination and supply of security assistance and training for Ukraine."

'It's impossible for Italy to send soldiers to Ukraine'

The Italian foreign minister on Friday ruled out both sending troops to Ukraine and the use of Italian weapons to hit targets inside Russia.

"It's impossible for Italy to send soldiers to Ukraine also to use our weapons in Russia," Antonio Tajani said at the doorstep of the informal NATO foreign ministers’ meeting in Prague.

In a statement, German Chancellor Olaf Scholz’s spokesman Steffen Hebestreit confirmed that German weapons can be used to strike Russian territory near Kharkiv.

Estonia's Foreign Minister Margus Tsahkna expressed that restrictions that are imposed on using donated weapons should be lifted for Ukraine to defend itself.

Dutch Foreign Minister Hanke Bruins Slot also said her country would not object if Ukraine used F-16 fighter jets supplied by the Netherlands to hit targets inside Russia.

Belgium, on the other hand, said it would not lift its opposition to Ukraine using arms it provides against targets in Russia, according to media reports citing a statement by Belgian Defense Minister Ludivine Dedonder's office.

'China is propping up Russia's war economy'

After the end of the informal meeting, Stoltenberg said that no final decisions were made on Friday but they made "significant progress" on several issues.

NATO's plans to play a greater coordinating role in the provision of equipment and training, and Ukraine's path to NATO membership were among the top issues that were discussed by foreign ministers.

Stoltenberg also noted that he has proposed that allies commit to a multi-year financial pledge of military aid to Ukraine.

He called on allies to commit to keeping the annual military aid for Ukraine at a minimum of €40 billion ($43.4 billion).

Asked about China's military assistance to Russia's war, a claim by the US that has been denied by China, Stoltenberg said China is "propping up Russia's war economy."

"Russia would not have been able to conduct the war of aggression against Ukraine without the support from China," noted the NATO chief.

He also said China is delivering "big amounts" of "dual-use equipment," advanced electronic equipment, including high end technology, semiconductors, and 90% of their micro-electronics.

"There is no doubt that China is playing a key role and enabling the Russians to produce the weapons they use to attack Ukraine," he noted, reiterating that Russia would not have been able to produce the missiles, the bombs, the tanks they are producing to attack Ukraine without China's help.