The Sun newspaper pressed Zelenskiy on his relationships with the senior commanders overseeing the war to beat back the Russian invasion.
For months, there has been speculation in Kyiv's political circles about a rift between Zelenskiy and Valery Zaluzhny, the commander-in-chief of Ukraine's armed forces.
The general has won praise for his military campaigns and is already seen as a rival to Zelenskiy for the presidency.
According to the constitution, regular presidential elections would have to take place on March 31 but Zelenskiy has called for the polls to be postponed given the war raging in the country.
"If a military man decided to do politics, it is his right, then he should enter politics and then he can't deal with war," Zelenskiy told The Sun.
"If you manage war keeping in mind that tomorrow you will do politics or elections, then in your words and on the front line you behave as a politician and not as a military man, and I think that is a huge mistake," he continued.
He added: "With all the respect to General Zaluzhny and to all the commanders who are on the battlefield, there is an absolute understanding of the hierarchy and that is it, and there can't be two, three, four, five."
Zelenskiy, who gives daily updates on the fighting, seemed to be hinting at an interview Zaluzhny gave to The Economist earlier this month in which the general warned the war had reached a stalemate.
"There is no stalemate," Zelenskiy fired back at the time.