- The whole of Europe could be at risk if Russia isn't challenged, according to the Dutch Prime Minister Mark Rutte.
- "If an aggressor is not challenged and can go about his business, it won't end with Ukraine," Rutte told CNBC's Steve Sedgwick.
- The Dutch prime minister also said he was "fairly optimistic" an agreement would be reached on whether tanks should be sent to Ukraine.
Dutch Prime Minister Mark Rutte said Thursday it was imperative that Europe continued to stand up to Russia's aggression, saying the region had to do "everything we can to help Ukrainians."
"If an aggressor is not challenged and can go about his business, it won't end with Ukraine. The whole West is threatened," Rutte told CNBC, as he discussed Europe's response to the war in Ukriane at the World Economic Forum in Davos.
Rutte referenced the 1938 Munich Agreement in his discussion with CNBC's Steve Sedgwick, where the allied forces agreed that Czechoslovakia would surrender its border regions and defenses to Nazi Germany.
"People feel that this is about values, that we cannot accept one country invading another country … It is also about our collective safety," he added.
Rutte also said Europe needs to do more to help Ukraine, but that the issue of sending tanks is "a sensitive decision."
"I do agree there is an argument to send [tanks] to Ukraine. There is also an argument to take the decision in conjunction with others, including our friends in the U.S.," he said, adding that he was "fairly optimistic" that the situation "could get to a landing spot."
"We have to do everything we can to help Ukrainians," Rutte said.
Ukraine has repeatedly asked its Western allies to provide tanks to help it fight Russia, which has caused tension between European countries, with some fearing the provision of weapons could further provoke Moscow.
But the region could be close to reaching an agreement.
"My understanding is that a deal has essentially been worked out," John E. Herbst, senior director of the Atlantic Council's Eurasia Center and a former U.S. ambassador to Ukraine, told CNBC Monday.
"We know that the laggard here has been Germany, and it seems that the Germans have now been persuaded that one, they'll let other countries which have Leopard tanks send them to Ukraine — that, I'm confident of — and I also think it's highly likely, but I'm not as confident, that you'll see Germany send some Leopards as well," he said.
When asked about Germany's contributions, Rutte said the country has always "done whatever needed to be done" to help Ukraine.
— CNBC's Holly Ellyatt contributed to this report.