As high-profile talks between Russian and Western officials continue Thursday, a top-ranking Ukrainian official has described how her country has to counter Russian “aggression” on a daily basis, while pushing for Ukraine to part of the discussions.

Olha Stefanishyna, Ukraine’s deputy prime minister for European and Euro-Atlantic Integration, told CNBC Thursday that “some of the talks are taking place without Ukraine, and it’s absolutely unacceptable.”

Speaking to CNBC’s Hadley Gamble in Kyiv, Stefanishyna continued that Ukraine “is the largest country in Europe, we are already part of the security architecture of the economic architecture. So it’s really time for us to be [at] the table.”

Stefanishyna’s comments come during a week that has seen a flurry of diplomatic meetings between Russian and Western officials.

U.S. and Russian representatives met in Geneva on Monday, followed by a meeting of the NATO-Russia Council in Brussels on Wednesday, ahead of the latest meeting at the Organization for Security and Cooperation in Europe in Vienna Thursday.

Talks are aimed at diffusing long-standing tensions between Kyiv and Moscow amid concerns that Russia, which has amassed thousands of troops at various points along its border with Ukraine, could be preparing to invade the country, although it has denied this.

Stefanishyna said that Ukraine was having to deal with aggression from Russia on a daily basis, and that that should also inform any negotiations with, or regarding, Russia.

“Whenever you’re stepping up with taking any decisions on Russia, you should consult and seek advice from Ukraine. Because we deal with them on a daily basis, we face the military aggression, the hybrid aggression, the energy and gas aggression, the security, cybersecurity aggression. This is all happening on a daily basis in Ukraine. This is the reality we live [with],” she noted.

There has been very little progress in talks so far this week, with a schism between what Russia wants and what it’s likely to get.

Russia has made a series of demands to the U.S. and NATO, primarily seeking assurances that there will be no eastward expansion of the Western military alliance and that Ukraine (and other former Soviet states) will never be allowed to join the organization, among other demands regarding military deployments.

NATO says it is willing to hold talks with Russia over arms control and missile deployments — but Secretary General Jens Stoltenberg said Wednesday that Moscow would not get any veto rights over countries joining the military alliance.

Russia’s representative — Deputy Foreign Minister Alexander Grushko — said Moscow would also be willing to continue talks but warned the situation is “very dangerous,” adding that Russia’s proposals could not be cherry-picked.

Ukraine aspires to join the EU, its neighbor to the West, and NATO, while Russia is looking to preserve its sphere of influence and power over former Soviet territories, setting the stage for more potential conflict. Russia is already operating under international sanctions for annexing Crimea from Ukraine in 2014 and its role in pro-Russian separatist uprisings in eastern Ukraine.

If Ukraine was a member of NATO then the alliance would be obliged to defend it in the event of an attack. As it is not, how far Western allies of the country are prepared to go remains uncertain.

The U.S. has reportedly largely settled on options for sanctions against Russia should it invade Ukraine. Speaking to Reuters, senior officials from the Biden administration said the U.S. is prepared to impose the sanctions as soon as any Russian tanks cross the Ukrainian border. Reports suggest Russia has about 100,000 troops deployed in the border area.

U.S. Deputy Secretary of State Wendy Sherman said Russia’s President Vladimir Putin should be prepared to face tough consequences if he orders an attack against Ukraine, with the prospect of more sanctions on Russia on the table.

“I think that if President Putin either through invasion, coercion, subversion, hybrid attacks, some other way to undermine the stability and the sovereignty and the governance of Ukraine … if he takes action in that regard, the entire international community will respond in a way that lets him know that we know exactly what has occurred here, and there are costs to continuing to act that way in the world community.”

Ukraine’s Stefanishyna said that any sanctions “should be targeted and timely” and that “it’s really important not to wait to when the actual invasion on the territory of Ukraine will take place.”

For its part, NATO has said that it will not compromise on its values when it comes to dealing with Russia. Speaking after meeting with Russia’s representatives on Wednesday, Stoltenberg said discussions had been difficult but necessary, noting “we are not ready to compromise on core principles — the right for every nation to choose their own path, and of course, also for NATO allies to protect and defend all our allies, including allies in the eastern part of our alliance.”

NATO had made it clear during the talks, he said, “that we are ready to engage in good faith in dialog with them on arms control, on measures for more transparency on military activities, risk reduction” and that . “we proposed many topics where we believe there is room for actually some real talks, dialog … and also a series of meetings where Russia and NATO can continue to sit down and work together.”

Stefanishyna said that Ukraine was grateful for the continuing support it had received from the U.S. and Europe but that the country was under “no illusion that any militaries of U.S. or NATO or any other country would fight for Ukraine on its territory.”

“We’re on our own, but it’s the interest of all allies, including U.S. to invest in Ukraine’s ability to deter and defend itself. That’s why we called on our allies through NATO to work on the bilateral level, also through NATO to ensure that Ukraine’s deterrence capability is growing stronger. Because … what happens if invasion happens? It’s all in our interest to make sure that Ukraine is capable to deter and defend so that the next day, we’re not talking about the Russian troops on the NATO borders.”

Another cold front throwing up further reason for conflict between Russia and Ukraine is the energy space with the latter standing to lose out on much-needed revenue from gas transits through the country once the Nord Stream 2 pipeline opens.

The pipeline is not yet working as German regulators are yet to give it the greenlight. In the meantime, Russia has been accused of trying to curb gas supplies (it supplies the EU with around 43% of its natural gas) to increase gas prices and to pressure politicians to give the pipeline the greenlight, although the Kremlin denies this.

The head of the International Energy Agency has accused Russia of intensifying Europe’s gas crisis by blocking some of the supplies. Speaking to reporters Wednesday, Fatih Birol said that the European gas market is experiencing disruptions “due to Russia’s behavior” and that low gas supplies to Europe coincide with heightened geopolitical tensions over Ukraine.  

The chief executive of Ukrainian state energy giant Naftogaz told CNBC Thursday that he thought it was absurd that Nord Stream 2 was not among the top priorities of international talks with the Kremlin, repeating his call for further sanctions on the gas pipeline to deter another Russian incursion.

“First, they should sanction Nord Stream 2, they should show again their firm stance to Putin. And for example, if somebody wants to discuss some further actions, if there is further aggression from the Russian side, they should be talking about Nord Stream 1. So I’m not saying that Nord Stream 2 is the only thing that should be on the agenda. But it should come first,” Yuriy Vitrenko told CNBC’s Hadley Gamble.

Stefanishyna agreed that “energy security” should be a part of current discussions with Russia, noting that an “energy crisis” would again be seen in Europe, she believed, claiming that Putin would “again play the whole [of] Europe with that.”