Former US President Donald Trump will be “against Americans” if he chooses to support Russia over Ukraine, President Volodymyr Zelensky told CNN Sunday, in a stark warning as his country enters a third year of full-scale war.

Speaking to CNN’s Kaitlan Collins in Kyiv as the war reaches a pivotal moment, Zelensky said he “can’t understand how Donald Trump can be on the side of (Russian President Vladimir) Putin.”

“It’s unbelievable,” he added.

Trump, who is on the verge of becoming the Republican presidential nominee after winning the South Carolina Republican primary, has in the past refused to say whether he wants Russia or Ukraine to win the war.

Zelensky said that he believed Trump — who also claimed he would end the conflict in one day if elected — did not understand Putin’s goals.

“I think Donald Trump doesn’t know Putin,” Zelensky said. “I know he met him… but he never fought with Putin. (The) American army never fought with the army of Russia. Never… I have a better understanding,” he said.

“I don’t think he understands that Putin will never stop,” he said.

Ukraine’s multiple challenges

The interview with CNN came at the end of a weekend in which Ukraine marked the two-year anniversary of Russia’s full-scale invasion, and as Kyiv is facing challenges on multiple fronts.

It suffered a major defeat earlier this month when Ukrainian troops withdrew from Avdiivka, an eastern city they held for a decade.

Zelensky and other Ukrainian and Western officials said Avdiivka was lost because troops did not have enough ammunition to defend it.

Yet despite the horrific consequences of these shortages, the US Congress continues to stall on President Joe Biden’s $60 billion military aid package for Ukraine.

Zelensky said that without US aid, Ukraine will not only struggle to make any new gains on the battlefield, but it will also find it difficult to keep defending itself this year.

“People will be prepared, but ammunition will not be prepared and brigades will not be ready… not only for our counter-offensive, they will not be ready to defend, to stay strong. It will be very difficult,” he said.

The timing is crucial as Zelensky said earlier on Sunday that Russia could attempt a new offensive as early as late May.

Ukraine’s new army chief Oleksandr Syrskyi is currently drawing up two versions of a plan on what to do next, he said. If Kyiv gets the US assistance, it will be able to start pushing back against Russia. If it doesn’t, it will have to focus on defending only.

Zelensky said that he has spoken to the House Speaker Mike Johnson about the aid package and was feeling optimistic after that conversation.

“He said that he will do everything to support Ukraine, and he’s on our side, and he understands how heroic our people, our soldiers and civilians (are),” he said.

Zelensky added that while he understands the US is heading into elections, he is hoping an agreement can be reached.

“If they will change their minds, it’s a big problem for us,” he said.

“I asked President (Biden)… ‘please, president, I’m asking you to help me and to help the Ukrainian people… please have one meeting with each other, Democrats and Republicans, and please, can you have a deal?’” he said.

Zelensky told CNN that Russia is spending “billions” on spreading false information about the war, and that it has been successful in using disinformation as a weapon – and in influencing the debate in the US.

“I was surprised that they are strong even in the United States, in the EU (European Union), all over the world. They put a lot of money (in)to this,” he said.

Inflating the number of Ukrainian casualties is just one example of how Russia is spreading false narratives, the president said. Earlier on Sunday, Zelensky disclosed for the first time the number of Ukrainian soldiers killed in the conflict so far: 31,000.

He said it was important to share the number because “we’ve had enough of the lies,” adding that even some US politicians have been sharing widely inaccurate numbers.

CNN cannot independently verify the numbers, which came on the weekend Ukraine marked two years since Russia’s full-scale invasion. US officials estimate some 70,000 soldiers have been killed and nearly twice that number wounded.

Asked by Collins about a claim made by US Senator JD Vance that the outcome of the war will not change even if Ukraine receives the money, Zelensky said Vance “does not understand what is going on here.”

“To understand it is to come to the frontline to see what’s going on… without this support. And he will understand that millions of people will be killed,” he added.

“He doesn’t understand it, of course, God bless you don’t have the war on your territory.”