MOSCOW, December 21. /TASS/. The United States and its allies need to understand that Russia simply "has nowhere to retreat" if its weapons appear in Ukraine, Russian President Vladimir Putin said on Tuesday at an expanded meeting of the Defense Ministry board.

"They [the US] simply do what they want. But what they are doing on the territory of Ukraine now, or trying to do and going to do — this is not thousands of kilometers away from our national border. This is at the doorstep of our home. They must understand that we simply have nowhere to retreat further," Putin said.

"We have specialists here, we are in constant contact with them. There is no hypersonic weapon in the United States yet, but we know when it will appear — they cannot hide it, everything is recorded, the tests are being conducted, successfully or unsuccessfully. So we approximately understand when it will happen," the President added.

Putin also believes that if the US deploys its weapons in Ukraine, it may try under the cover of these weapons to push Kiev to attack Crimea.

"They will put hypersonic weapons in Ukraine, and then, under their cover <...> they will arm and push extremists from the neighboring state against Russia, including into certain regions of the Russian Federation, for example, Crimea, under advantageous circumstances as they believe," the head of state went on.

"Do they think we don’t see these threats? Or do they think that we are so weak-willed to simply look blanky at the threats posed to Russia? That is the problem: we simply have nowhere to move further, that’s the question," Putin said.