Visiting Australia, the leader of the pending NATO member said Vladimir Putin's invasion and occupation of neighboring Ukraine had exposed both European weaknesses and strategic blunders in dealing with Russia, AFP said.

"I must be very honest, brutally honest with you, Europe isn't strong enough right now. We would be in trouble without the United States," she told Sydney's Lowy Institute think tank.

Marin insisted Ukraine must be given "whatever it takes" to win the war, adding that the United States had been pivotal in supplying Kyiv with the weapons, finance and humanitarian aid necessary to blunt Russia's advance.

"We have to make sure that we are also building those capabilities when it comes to European defense, the European defense industry, and making sure that we could cope in different kinds of situations," she said.

Finland won independence from Russia almost 105 years ago and inflicted heavy casualties on an invading Soviet army soon after despite being hugely outgunned.

The 37-year-old Finnish leader decried European Union policies that had stressed the importance of engagement with Putin and said the bloc should have listened to member states who were part of the Soviet Union until it collapsed.

Since joining the European Union in 2004, countries such as Estonia and Poland have urged fellow EU members to take a tougher line on Putin, a stance tempered by France, Germany, Italy and Greece -- which favored closer economic ties with Moscow.

"We should have listened to our Baltic and Polish friends much sooner," Marin said.

"For a long time, Europe was building a strategy towards Russia to close our economic ties, to buy energy from Russia... we thought that this would prevent a war."

Marin added that this approach had been "proven entirely wrong".

"They don't care about economic ties, they don't care about the sanctions. They don't care about any of that."