Russian President Vladimir Putin, after months of dropping veiled threats about nuclear weapons after he ordered his full-scale invasion of Ukraine over two years ago, is now saying that Europe is "defenseless" and that Russia wouldn't need a nuclear weapon to defeat Ukraine or its allies.

Russia, he said during a panel discussion at the St. Petersberg International Economic Forum, has "more [tactical nuclear weapons] than there are on the European continent, even if the United States brings theirs over," reported BBC Russian editor Steve Rosenberg. 

Putin further told Russian foreign policy expert Sergei Karaganov, who was questioning him, that "Europe does not have a developed [early warning system]. In this sense, they are more or less defenseless."

Meanwhile, Putin said he's not ruling out changes to the Russian nuclear doctrine, which outlines the conditions necessary to use nuclear weapons. 

"This doctrine is a living tool, and we are carefully watching what is happening in the world around us and do not exclude making changes to this doctrine," said Putin. "This is also related to the testing of nuclear weapons.”

The St. Petersberg International Economic Forum, often referred to as the Russian Davos, has widely been seen as a sign that the country is open to cooperation. Still, Russia remains under heavy worldwide sanctions because of the war in Ukraine, and tensions remain high. 

Putin earlier this week, while meeting with international news agency leaders in St. Petersberg, said Russia could supply conventional long-range missiles to countries for use in striking Western targets.

His threat comes after NATO allies have allowed Ukraine to use Western-supplied weapons to hit targets inside Russian territory, and he doubled down on his comments Friday.  

"We are not supplying those weapons yet, but we reserve the right to do so to those states or legal entities which are under certain pressure, including military pressure, from the countries that supply weapons to Ukraine and encourage their use on Russian territory," said Putin. 

Russian state TV host Vladimir Solovyov told Rosenberg that the Russians would base the weapons "wherever we think it is necessary."

"As President Putin made clear, we'll investigate this question," he added. "If you are trying to harm us, you have to be pretty sure we have enough opportunities and chances to harm you."

Solvyov also rejected the argument that such saber-rattling is a bluff. 

"It's always a bluff until the time when it is not," he said. "You can keep thinking that Russia is bluffing and then, one day, there is no more Great Britain to laugh at. Don't you ever try to push the Russian bear thinking that 'Oh, it's a kitten, we can play with it.'"

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