Ukrainian President Volodymyr Zelenskiy has warned his country's military leadership of getting involved in politics.
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.
Ukraine's defence minister said on Tuesday that no decision had been taken for now to remove two senior military commanders following media reports that they could be sacked.
The comment by Rustem Umerov at a news conference was the strongest hint yet that Ukraine was considering the possibility of firing Joint Forces Commander Serhiy Nayev and Oleksandr Tarnavskyi, chief of the "Tavria" military command.
"I must say that a decision has not yet been made but that we are doing everything possible to improve efficiency. If this happens, we will communicate it very openly," he told reporters when asked to comment on reports commanders could be fired.
Any such move, he said, could also be related to issues that had been raised before his appointment in September when he replaced Oleksii Reznikov as minister, he said.
The defence ministry has previously dismissed reports about a possible looming shake-up.
Tarnavskyi oversees the Tavria military command which spearheaded Ukraine's much-vaunted counteroffensive in the southeast but failed to force a significant breakthrough in the face of heavily-defended Russian lines.
Umerov's comments on Tuesday came at a news conference in Kyiv with his German counterpart.
At the event, he told reporters he was focused on the military adopting NATO standards and delivering the needs of the military in his role.
"These standards are very important... Every unit and every commander knows these needs and we must meet them," he said.
Australian Associated Press