KYIV, July 7 - President Volodymyr Zelensky told CNN's Wolf Blitzer on Thursday that Ukraine is unwilling to cede any of its land to Russia, standing firm that a concession of Ukrainian territory won't be part of any diplomatic negotiations to end the war, CNN reported.

Ukrainians are not ready to give away their land, to accept that these territories belong to Russia. This is our land," Zelensky said in an exclusive interview aired Thursday on CNN's "The Situation Room."

We always talk about that, and we are intending to prove it," he added.

Zelensky spoke to CNN at the same time as one of his top Western allies, British Prime Minister Boris Johnson, announced he would be resigning. Speaking in Ukrainian via a translator, Zelensky said he was confident that Britain's policy toward Ukraine "will not be changing" even if the country's leadership is in tumult.

He resigned not because he was in Ukraine. I think on the contrary, what Johnson has been doing for Ukraine was helping us a great deal. I consider him a friend of Ukraine, but I think his society also supported Ukraine in Europe. That's why I think the UK, it's on the side of good, on the side of Ukraine," Zelensky said.

And I'm sure the UK policy toward Ukraine is not ... changing because of Boris Johnson's resignation. Our relations obviously gained a lot from Boris Johnson's understanding of things. We went through a lot of dramatic moments quite quickly. The help we needed was delivered rather quickly ... if (his resignation) will affect this speed of help I don't know. I will pray to God it won't be affecting that help."

Russia's war with Ukraine has now lasted for more than four months, with no sign of either side backing down soon. Ukraine's early successes forced Russia to scale back its initial aims of toppling Kyiv, and Moscow's forces have now focused on taking territory in eastern Ukraine. Russian forces have now occupied most of the Luhansk region, outside of a few pockets of resistance, and are pressing toward cities in Donetsk.

CNN reported last week that White House officials are losing confidence Ukraine will ever be able to take back all of the land it has lost to Russia since the war began, even with the aid of heavier and more sophisticated weaponry that the US and its allies plan to provide Kyiv.

Zelensky acknowledged that Russia controls "almost all the Luhansk region," saying that his forces are now "fighting on the outskirts of this region." He said that Kyiv retreated to avoid mass losses of troops.

I don't even understand what exactly they're controlling there. They ruined towns, school. They are the occupiers of the rubble?" Zelensky said.

Zelensky expressed gratitude for the military support that Ukraine has received from the United States, which has provided weapons with greater capability as the war has dragged on, while urging the West to continue providing military support to help Ukraine keep up its fight.

(The) United States are helping Ukraine, helping a lot, but it's not enough in order to win. I hope my trust will speed up this help to Ukraine," Zelensky said. "We want the increment of this help -- we're fighting for our land, we don't want people from different countries fight for our territory. But the US are a world economy and can help us with both arms and finances.

And also, the US can influence the decisions of the European countries -- this is also the political support. I have to be honest, some countries in Europe want a balance between Russia and Ukraine. But owing to the US help they started supporting us." (cnn/ez)