Boxing icon Klitschko signs up for Ukraine reserve army amid Russia tensions

Vitali Klitschko has warned Russia against attacking Ukraine amid rising tensions between the two neighbors, with his brother Wladimir enlisting for their homeland's reserve army and vowing to defend Kiev.

"Before our enemies make an attack against Ukraine they have to see we are strong, they have to see how strong we will be, it will be a very painful price for everyone," Kiev mayor Vitali said on Wednesday to CNBC.

Revealing that he hoped diplomats both in Ukraine and other countries could "stop this aggression [in a] diplomatic way," Vitali stressed that Ukrainians will otherwise have to "be prepared for any scenario” and "have to prepare to take weapons in our hands."

That is something that self-proclaimed "activist" Wladimir is supposedly willing to do after enlisting for his homeland's reserve army.

"It is is a naked part that is in me, that I cannot leave just like that. When seeing that my country is geopolitically struggling, I'm right here," Wladimir explained to reporters as his brother opened Kiev's first reservist recruitment center.

"I can't stand still, and I want [to help].

"That's why I'm here and that's why I signed up for territorial defense, of the country and the city," he said, though conceding like Vitali that hopefully "smart enough" steps will be taken to avoid conflict in the east of the country.

"One district from here, my little girl is going to school. The school is currently closed because the ambassadors have sent the families home," Wladimir revealed.

"It is the love, the love for my city, my home, my family, my neighbors, my daughter that has brought me here today, that I took this initiative and am now taking part in this territorial defense."

Vitali publicly blasted Germany recently and branded an offer of 5,000 helmets to Ukraine by Berlin a "joke."

"The behavior of the German government leaves me speechless," he said to Bild last week.

"The defense ministry apparently hasn’t realized that we are confronted with perfectly equipped Russian forces that can start another invasion of Ukraine at any time.

"What kind of support will Germany send next?" Vitali asked. "Pillows?"

But to German reporters, Wladimir showed more respect towards the country where the brothers spent the majority of their careers being promoted by Wilfried Sauerland. 

"I would say I am grateful to Germany, because no other country – we are always very critical – has invested into Ukraine as much as Germany has in the past few years," Wladimir said, as reported by Reuters.

"Germany is the number one, and then all the other countries that supported us. I want to say 'thank you' for this support."

READ MORE: ‘No animosity’ as Russia and Ukraine prepare for rare showdown

To CNBC, however, Wladimir criticized the West for showing "weakness" and said that "there's never enough" regarding what the US can do to help Ukraine.

"I believe that sometimes the West shows weakness in certain situations and that we need to be more united and protect each other and protect our interests, protect our democracy that we’ve been fighting for and developing in the Western world," Wladimir demanded.

"I believe this unity will give us enormous strength," he went on, insisting there should be better communication among allies in the West while a potential Russian invasion of Ukraine would pose an "issue for everybody."

Speaking on the damage being done to Ukraine's economy amid the crisis, with inflation rising to 10% in December, Vitali claimed that it has "touched everyone in Ukraine and so yes, of course it's hard for Ukraine and for our economy."

"But right now the question [is about the] integrity and independence of our country," he concluded.

Russia has engaged in dialogue with the US amid the tensions, asserting that Western powers are ignoring Moscow's legitimate security concerns by moving to bring Ukraine into NATO.

The US has accused Russia of amassing troops on the border with Ukraine, with the White House previously claiming an “invasion” was “imminent.” 

The government in Kiev, however, said there was no cause for panic, while Moscow rejected the accusations as “fake news.”