Ukrainian President Volodymyr Zelensky in an interview with AFP on Friday warned Russia could intensify its offensive and said Kyiv would only accept a "fair peace" despite the West's calls for a quick solution.
Zelensky also repeated pleas for allies to send more air defence and fighter jets and said the "biggest advantage" for Russia was a ban on Ukraine using Western-donated weapons to strike Russian territory.
With a mobilisation law coming into force on Saturday, he admitted issues with staffing and "morale" in Ukrainian ranks, which have been often outgunned and outmanned as the third year of the war grinds on.
While Russian troops have made gradual advances in recent months, it has seen larger gains along the northeastern border in an offensive that began on May 10 in Kharkiv region.
But Zelensky said on Friday that Ukraine would hold its defensive lines and stop any major Russian breakthrough.
"No one is going to give up," said Zelensky, who has been the face of Ukraine's resistance against Russia since the invasion began in February 2022.
Zelensky also rejected French President Emmanuel Macron's call for an Olympic truce during the Paris Games, saying it would hand an "advantage" to Moscow by giving it time to move around troops and artillery.
He said Ukraine and its Western allies had the "same values" but often "different views", particularly on what the end of the conflict might look like.
"We are in a nonsense situation where the West is afraid that Russia will lose the war. And it does not want Ukraine to lose it," Zelensky said.
"Everyone wants to find some model for the war to end faster," he said, when asked about the possibility of a scenario for ending hostilities like the one that established a dividing line on the Korean peninsula.
The president urged China and countries from the developing world to attend a peace summit with dozens of leaders being hosted by neutral Switzerland next month to which Russia has not been invited.
He said global players like China "have influence on Russia. And the more such countries we have on our side, on the side of the end of the war, I would say, the more Russia will have to move and reckon with."
The 46-year-old former comedian wore one of his trademark khaki outfits for the interview in Kyiv -- his first with foreign media since the start of Russia's Kharkiv region offensive.
"We want the war to end with a fair peace for us," while "the West wants the war to end. Period. As soon as possible. And for them, this is a fair peace," he said.
Zelensky said the situation in the Kharkiv region, where thousands of people have been forced to flee their homes, was "controlled" but "not stabilised".
An AFP estimate based on data from the Institute for the Study of War (ISW) showed Russian forces have advanced more than 278 square kilometres (107 square miles) in their offensive-- their biggest gains in a year and a half.
Zelensky said Russian troops had penetrated between five to 10 kilometres along the northeastern border before being stopped by Ukrainian forces.
Russia's offensive "could consist of several waves. There was the first wave" in Kharkiv region, he said.
Zelensky played down Russia's gains in the offensive so far but added: "We have to be sober and understand that they are going deeper into our territory. Not vice versa. And that's still their advantage."
Speaking about the offensive during a visit to China on Friday, Russian President Vladimir Putin said it was a response to Ukraine shelling border regions.
"I said publicly that if this continues, we will be forced to create a security zone," he said.
When asked whether Russia planned to capture the city of Kharkiv, which has over a million inhabitants, Putin said: "As for Kharkiv, there are no such plans as of today."
But Zelensky said that Russian forces "want to attack" the city although they realise it would be "very difficult".
"They understand that we have forces that will fight for a long time," he said.
He also said Russia did not have enough forces for "a full-scale offensive on the capital like the one they had at the beginning of the offensive".
But he emphasised that Ukraine and its Western allies should not show weakness and called for the deployment of two Patriot batteries to defend the skies over the Kharkiv region and show Ukraine's resilience.
"They are like a beast... If they feel a weakness somewhere in this direction, they will press on," he said.
In the interview, he said Ukraine only had "about 25 percent of what we need" to defend the country in terms of air defence.
He also said "120 to 130" F-16 fighter jets or other advanced aircraft were needed "in order to have parity" with Russia.
He was highly critical of restrictions on striking Russian territory with Western arms, although Britain and the United States have hinted in recent days that these bans could be eased.
"They can fire any weapons from their territory at ours. This is the biggest advantage that Russia has. We can't do anything to their systems, which are located on the territory of Russia, with Western weapons," he said.
When asked about the issue during a visit to Ukraine this week, US Secretary of State Antony Blinken said that "ultimately Ukraine has to make decisions for itself about how it's going to conduct this war."
On a more personal note, Zelensky said his sense of professional pride and duty helped him keep going.
"I'm just a very responsible person. I was just raised to be such a person... I know that what I do, I have to do better than anyone else," he said.
But he said his comedy days were behind him: "I don't make anyone laugh. It seems to me that today it's the opposite."
