"We are following this most closely, you know that our relevant services have long had information that one way or another, people who call themselves advisers and who are directly related to NATO are actually on the territory of Ukraine," Peskov told reporters.
On Sunday, Polish Foreign Minister Radoslaw Sikorski said that NATO soldiers are already present in Ukraine, without providing any further details.
Following a Paris-hosted conference on Ukraine on February 26, French President Emmanuel Macron said Western leaders had discussed the possibility of sending troops to Ukraine and, although no consensus had been reached in this regard, nothing could be ruled out. On Friday, Sikorski said that the presence of NATO forces in Ukraine "was not unthinkable," adding that he appreciated Macron's initiative on the possibility of sending Western troops to Ukraine. Meanwhile, Polish President Andrzej Duda said that Poland needed to build a large airport for the transfer of NATO troops.
Meanwhile, there is an increased activity of drone attack attempts by the Ukrainian armed forces in Russian regions, but Russian military and air defense systems are coping well, Kremlin spokesman Dmitry Peskov said.
"Yes, indeed, there is increased activity. Air defense systems and our military are working," Peskov told reporters.
Commenting on calls for negotiations between Kiev and Moscow, the official said that they had recently been met with harsh denial by Kiev, adding that Ukraine does not "allow the possibility of conducting any negotiations."
By denying negotiations, Ukraine draws support from the assurances of many European countries to continue to do everything in order to defeat Russia, the official said.
"This is the deepest delusion, a major mistake. And the course of events, first of all, on the battlefield, most clearly testifies to this," Peskov said.
Moscow is also aware of reports about former US President Donald Trump's peace plan for Ukraine, but without any knowledge about the details of its contents, Peskov said.
"Yes, we have seen it, but we have nothing to say because no details are given there. It is unclear what kind of plan this might be, so it is not possible to say anything specific on the matter," Peskov told reporters.
When asked about reports claiming that Russia can use nuclear weapons in Ukraine, he called them part of yellow press.