• Republican presidential nominee Donald Trump's decision to pick Sen. JD Vance as his vice presidential running mate will have sent chills down spines in Kyiv on Tuesday morning.
• Ohio Republican Vance is a staunch proponent of Trump's "America First" policy, and is ambivalent over U.S. intervention in foreign affairs.
• He has strongly opposed more aid for Ukraine and has suggested Kyiv be prepared to cede territory to Russia in order to achieve peace.

Republican presidential nominee Donald Trump's pick of Sen. JD Vance as his vice presidential running mate will have sent chills down spines in Kyiv on Tuesday morning.

Ohio Republican Vance is a staunch proponent of Trump's "America First" policy vision and is generally ambivalent over U.S. intervention in foreign affairs. He has also strongly opposed more aid for Ukraine.

To add to Ukrainian President Volodymyr Zelenskyy's concerns as he contemplates the likelihood of another Trump presidency, Vance has argued that the U.S. should encourage Ukraine to strike a peace deal with Russia, and that Kyiv should be prepared to cede land to its invader.

"It ends the way nearly every single war has ever ended: when people negotiate and each side gives up something that it doesn't want to give up," Vance told reporters in December, adding, "no one can explain to me how this ends without some territorial concessions relative to the 1991 boundaries."

Vance, who once served in the Marines, has also been dismissive of concerns that territorial concessions by Ukraine — an unthinkable notion for Kyiv — would not be enough for Russian President Vladimir Putin and that the rest of Europe could be at risk.

"If you look at the size of the Russian armed forces, if you look at what would be necessary to conquer all of Ukraine, much less to go further and further west into Europe, I don't think the guy's shown any capacity to be able to accomplish these, these imperialistic goals, assuming that he has them," Vance said, NBC News reported.

In February, Vance penned an opinion piece for the Financial Times in which he suggested that Europe had been overreliant on the U.S. and that the region should shoulder the burden of defending its neighbor Ukraine.

He also echoed the Trumpian view that NATO members in the region were not spending enough on defense — a valid accusation in the past, analysts say. However, the record is getting better and NATO said last week that 23 out of 32 allies are now meeting the 2% of gross domestic product defense spending goal.

"The United States has provided a blanket of security to Europe for far too long," Vance wrote in the FT.

"As the American defence budget nears $1tn per year, we ought to view the money Europe hasn't spent on defence for what it really is: an implied tax on the American people to allow for the security of Europe."

"Nothing in recent memory demonstrates this more clearly than the war in Ukraine," he said, adding that America has been "asked to fill the void at tremendous expense to its own citizens."

'God help Ukraine'

That was the three-worded response in an email Monday of Timothy Ash, emerging markets strategist at BlueBay Asset Management, on hearing the news that Vance had been picked as Trump's running mate.

Ash has previously questioned Vance's position on Ukraine and the suggestion that Europe should bear the sole responsibility of helping Ukraine to defend itself against Russia.

Responding to Vance's FT opinion piece back in February, Ash warned that "the stark reality is that without very immediate military backing and supplies from the U.S., Ukraine could lose the war, or at least significantly more territory sufficient to question its own viability as a state."

"Vance et al should ask themselves what that would then mean for Europe and the US, in terms of transatlantic security," Ash added.

When Vance made his comments regarding Ukraine to the press in December, Zelenskyy was preparing to meet members of Congress on Capitol Hill to press them to pass a much-needed $61 billion aid package for his country as its forces began to run low on artillery and ammunition.

The aid was eventually passed in April, giving Ukraine a lifeline as Russia began a new offensive in the northeast of the country. Since then, and as the aid has trickled down to the front lines, Ukraine has continued to petition its international partners for more aid, air defense systems and fighter jets in order to help it turn the tide in the war.

Such a prospect remains far off, however, and fighting remains intense. After almost 2½ years of fighting, the war has fallen out of international headlines and domestic political upheavals and priorities have demanded the attention of Ukraine's allies in NATO.

Asked on Monday about his thoughts on a possible Trump administration after the U.S. election, Zelenskyy told reporters that Ukraine had "good relations" with both Democrats and Republicans.

"In Utah [which Zelenskyy visited last week for the National Governors Association meeting], we met with the Republicans' senators, and they respect Ukraine and me. I am aware of Trump's view about how to end this war. If he becomes a president, we will continue the work. Most of the [Republican] party supports us," Zelenskyy said.

The Trump-Vance ticket

One of Ukraine's biggest concerns is the U.S. presidential election and whether, as polls suggest, Trump will win a second term in office come November.

Trump has always appeared ambivalent over the war in Ukraine and continuing aid. During his time in office from 2017-2021, the former president displayed increasingly warm relations with Russia's Putin. He has previously said he would end the war in Ukraine "in 24 hours" if he was in charge, without giving any details of how he would do so.

The comment was an ominous one for Ukraine, however, suggesting Trump could be tempted to pull the rug on further aid.

Keen to ring-fence and seemingly "Trump-proof" NATO assistance for Ukraine, the military alliance which met in Washington last week, reaffirmed its long-term support for Ukraine and the country's ambitions to join the Western defense bloc.

The specter of a possible Republican administration also loomed large over the gathering, however, with analysts saying the alliance was likely nervous about a potential change in direction in U.S. policy under a Trump presidency.

"We don't know who will be elected but what we do know is that the likelihood of Trump being elected has increased," Guntram Wolff, senior fellow at the Bruegel think tank, told CNBC last week.

"Donald Trump would mean a big break with a couple of NATO policies, in particular on the question of Ukraine and support to Ukraine. There are rumors that there are some peace plans that have been proposed by thinkers around Trump that would imply that Ukraine gives up a lot of territory, and would have to negotiate with Russia," he said.

Wolff said such a move would be a "dangerous route" to take, as it would "embolden the Russian dictator Putin and it would still leave open the question of who guarantees the security of Ukraine after that. So I think there's a lot of really big issues at stake here," he added.

For now, analysts see little chance of a cease-fire, or any desire from Kyiv to seek one with Russia as the war is still in very much of an "active phase" in which both sides believe they have a chance of overpowering the other.

"Russia recently set out its demands for any kind of ceasefire which are very maximalist, there wouldn't be much room for negotiation there, and I think that sends a signal that negotiations are not imminent or something being looked at by either side in the short or medium-term," Anna Gilmour, head of country risk and geopolitics at Verisk Maplecroft, told CNBC's "Squawk Box Europe" last week.

"I see that, and ongoing NATO support for Ukraine, as a sign that we're not going to see an end to the fighting."