• Moscow has denied that it plans to invade neighboring Ukraine, a former part of the Soviet Union, but has moved around 130,000 soldiers, tanks, missiles, and even fresh blood supplies to the border.
• In 2014, Russia seized and annexed Crimea, a part of Ukraine.
• One man living in Ukraine's east told CNBC Ukrainians "just want peace" but that many are preparing for military conflict.

International tensions are high as Russian troops and military equipment continue to be amassed at its border with Ukraine, creating an uncertain future for millions of Ukrainians.

Ukraine's President Volodymyr Zelenskyy warned on Tuesday that any military confrontation with Russia would result in a "full scale" war on European soil.

Moscow has denied that it plans to invade neighboring Ukraine, a former part of the Soviet Union, but has moved around 130,000 soldiers, tanks, missiles, and even fresh blood supplies to the border, according to NBC News.

Russia is demanding that Ukraine never be permitted to become a member of the NATO military alliance, and has also said it wants the organization to roll back its presence in Eastern Europe.

Maksym, a Ukrainian living in the city of Kramatorsk — around 100 miles from the Russian border — told CNBC in a phone call that the mounting tensions were "scary." Kramatorsk, in Ukraine's east, was captured by pro-Russian separatists in 2014 after Moscow's seizure and annexation of Crimea from Ukraine. It was later regained by government forces.

"We have been living in this situation for seven years," Maksym said. "A lot of people — I think 30 to 40% of the population of my city — have emergency bags, like cash, documents and a full tank of gas in their cars. We're ready."

Around 13,000 people in east Ukraine have died in an ongoing conflict between Ukrainian troops and pro-Russian separatists in the Donbas region, where Kramatorsk is.

'We lost a part of our lives'

Maksym added that if there was any military confrontation, he would move north-west to either the capital, Kyiv, or a city in Ukraine's west, like Lviv or Ivano-Frankivsk.

"We have a big history with the Russian people. I have relatives who live in Russia and Belarus, and other post-Soviet Union countries," he told CNBC. "We're like one big country, but ... I think Russia wants to recreate the Soviet Union."

Under the Soviet regime in the 20^th century, an estimated 3 to 4 million Ukrainians — around 13% of the population — died in a famine brought about by communist leader Joseph Stalin's policies. The famine, known as Holodomor, has been referred to by the EU as genocide.

In documentary footage released by Russian state TV last year, Putin dubbed the union's collapse "a disintegration of historical Russia" that plunged Russians in newly independent countries into "a major humanitarian tragedy," Reuters reported.

Maksym noted that before Russia invaded Crimea in 2014, a lot of Ukrainian people went there for their summer vacations.

"But now we don't have this place," he said. "It's like we lost a part of our lives."

"When I was born, Crimea was a part of Ukraine and so all my life I have felt that Crimea is Ukraine," Maksym said. "But now it's like you have an apartment and some people have come in and taken one room, and you have your own apartment but you can't use one of the rooms. And that's wrong."

'We just want peace'

During a press briefing on Friday, analysts at thinktank Chatham House told reporters 24% of Ukrainians surveyed in recent weeks said they were ready to physically defend Ukraine, on top of those who had already joined its growing volunteer army.  

But according to Maksym, most ordinary people he knows "just want to live in peace."

"We don't want any aggressive moves to Ukraine," he said. "We don't want to fight — we just want peace. But I don't know how to create it. Western countries have a lot of smart people who know how to stop [a conflict], so I hope we'll get a decision [that lets us] live a happy and healthy life."

U.S. Secretary of State Antony Blinken said on Tuesday that the U.S. and its allies were "committed to preventing a conflict that is in no one's interest," but added that America was "ready to impose severe costs if Russia further invades Ukraine."

During talks with his Russian counterpart, Sergei Lavrov, on Tuesday, Blinken said now was the time for Russia to pull back troops if Putin "truly does not intend war or regime change," Reuters reported.

Meanwhile, Putin said on Tuesday that the U.S. was using Ukraine as a tool to "contain Russia."

He's been stating that position for a while. Last July, the Kremlin published an article by Putin in which the Russian President said Ukraine had gradually been "dragged into a dangerous geopolitical game aimed at turning Ukraine into a barrier between Europe and Russia."

— CNBC's Holly Ellyatt contributed to this article.