President Volodymyr Zelenskiy is not aware of any details of US president-elect Donald Trump's plan to end the Ukraine war quickly, saying he is convinced a rapid end would entail major concessions for Kyiv.
The Ukrainian leader's comments came after he urged leaders at the European Political Community summit in Budapest to apply an approach of "peace through strength" to confront the threat posed by Russia.
Zelenskiy told reporters he believed Trump wanted to end the war with Russia quickly, but he had not discussed a plan with him.
"If it's just fast, it means losses for Ukraine. I just don't yet understand how this could be in any other way. Maybe we do not know something, do not see," he said on Thursday.
Trump's election victory this week has escalated a sense of great uncertainty for Ukraine's war effort at a perilous moment with Moscow's troops making their most rapid advances in months and North Korean troops deployed in Russia's Kursk region.
Zelenskiy was among the first leaders to congratulate the president-elect, who on the campaign trail criticised the scale of US military and financial support for Kyiv and vowed to end the war quickly, without saying how.
The United States has been Kyiv's most important ally in the war and Zelenskiy has pointedly praised Trump's election victory in his statements.
He spoke by telephone with the Republican late on Wednesday and described the conversation as "excellent".
"I believe President Trump really wants a quick decision. Wants - it does not mean that it will happen. And I'm (talking) here without any reproach, I am just saying that we are where we are," he told reporters.
In Russia, whose troops control around a fifth of Ukrainian territory, President Vladimir Putin said on Thursday that he was ready to speak to Trump, as any ideas on facilitating an end to the Ukraine crisis merited attention.
Zelenskiy said: "We must be preparing for any decision. We want a fair end to the war. I am sure that the imminent end of the war means losses."
Zelenskiy used harsh language to oppose the idea of a ceasefire in the war without security guarantees being provided to Kyiv, something Ukraine says it needs to prevent Russia launching an even bigger offensive further down the line.
"It's a very scary challenge for our citizens: first a ceasefire, then we'll see. Who are you? Are your children dying?"
"A ceasefire is being proposed, for instance by a leader who is against having Ukraine in NATO. Imagine ... this is nonsense and disharmony."
Earlier at the Budapest summit, Zelenskiy called on European leaders to apply an approach of "peace through strength" to confront the threat posed by Russia.
"The concept of 'peace through strength' has proven its realism and effectiveness more than once. Now, it is needed once more," Zelenskiy said.
He stressed his country needed firm support from European leaders, some of whom he criticised for advocating concessions to Russia.
It was "unacceptable for Ukraine and suicidal for all Europe", he said.
"And what's next? Should Europe seek the favour of Kim Jong-un in hopes that he, too, will leave Europe in peace?" Zelenskiy said alluding to North Korean troops apparently deployed by Russia in the border region with Ukraine.
"We need sufficient weapons, not just support in talks. Hugs with Putin won't help," the Ukrainian leader said in an apparent reference to pictures showing United Nations chief Antonio Guterres hugging President Vladimir Putin at a summit in Russia.
In Ukraine, a Russian guided bomb attack on Ukraine's southeastern city of Zaporizhzhia killed four people and wounded 33, destroying houses and damaging an oncology centre.
A four-month-old girl and two boys, aged one and 10, were among the wounded, regional governor Ivan Fedorov said on Telegram.
Russia launched six bombs at the city, all of which hit civilian infrastructure, including houses and a residential building, according to Fedorov.
Russian troops have recently stepped up attacks on Zaporizhzhia and the surrounding region.
They carried out almost 11,000 attacks on the region in October alone, according to Fedorov.
