A representative of President Volodymyr Zelenskyy described signatories to the Budapest Memorandum as a reason Ukraine is at war, citing their failure to hold up their end of the agreement.

"They signed their obligation to protect Ukraine, to provide the security and safety," Fedir Venislavsky, President Zelenskyy's representative to Ukraine's Constitutional Court, told Fox News. 

"Which means when Ukraine gave up its nuclear potential … Ukraine was confident the other countries who have signed all of those agreements were going to guarantee its territorial integrity, it's independence and it's sovereignty."

Explosions in Lviv

Explosions rocked the western Ukrainian city of Lviv Saturday, March 26, 2022, near an oil depot. (Fox News)

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"Unfortunately, we're deeply sorry" the signatories of the Budapest Memorandum and the Charter "did not perform" and "provide the security of Ukraine" and "there is a war because of that going on in our territory," Venislavsky explained.

Zelensky

In this image from video provided by the Ukrainian Presidential Press Office and posted on Facebook, Ukrainian President Volodymyr Zelenskyy speaks in Kyiv, Ukraine. (Ukrainian Presidential Press Office via AP)

On Saturday, smoke billowed over the city of Lviv in western Ukraine after multiple explosions were heard near an oil depot. In a speech during Qatar's Doha Forum, President Zelenskyy called on the United Nations to do more to intervene in the conflict and aid Ukrainians.

Explosions in Lviv

Explosions rocked the western Ukrainian city of Lviv Saturday, March 26, 2022, near an oil depot. (Fox News)

The Budapest Memorandum "says that whatever countries would sign that, they would guarantee the safety and security of Ukraine. And there's the charter about the special partnership between NATO and Ukraine and all the signatories," Venislavsky added.

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"Innocent people are dying every day simply because we believed that those countries were going to provide what they obliged for."

First row from right, Turkey's President Recep Tayyip Erdogan, Britain's Prime Minister Boris Johnson, U.S. President Joe Biden, NATO Secretary General Jens Stoltenberg, Belgium's Prime Minister Alexander De Croo and leaders of the U.S.-led military alliance, pose for a photo at NATO headquarters in Brussels, Thursday, March 24, 2022.

First row from right, Turkey's President Recep Tayyip Erdogan, Britain's Prime Minister Boris Johnson, U.S. President Joe Biden, NATO Secretary General Jens Stoltenberg, Belgium's Prime Minister Alexander De Croo and leaders of the U.S.-led military alliance, pose for a photo at NATO headquarters in Brussels, Thursday, March 24, 2022. (Brendan Smialowski, Pool via AP)

Venislavsky said the failure to protect Ukraine will have lasting consequences.

Fedir Venislavsky, President Zelenskyy's representative to Ukraine's Constitutional Court

Fedir Venislavsky, President Zelenskyy's representative to Ukraine's Constitutional Court (Fox News)

"After the Ukrainian case, I think there are going to be a lot of doubts in the world regarding international obligations that are given in exchange for whatever concessions," Venislavsky said.