Putin said in the interview published on Wednesday that Russia was technically ready for nuclear war and that if the U.S. sent troops to Ukraine, it would be considered a significant escalation of the conflict.

Commenting on Putin's words, White House spokesperson Karine Jean-Pierre told reporters that Washington understood that the Russian leader was restating Moscow's nuclear doctrine, but accused Russia of deploying "reckless and irresponsible" nuclear rhetoric throughout the Ukraine conflict.

Kremlin spokesman Dmitry Peskov said on Thursday that Putin had merely been answering a journalist's questions on the subject and restating the already well known circumstances in which Russia would theoretically be forced to use nuclear weapons.

Peskov also drew attention to the fact that Putin had said in the same interview that the idea of using tactical nuclear weapons in Ukraine had never crossed his mind.

Asked about the White House comments, Peskov said:

"This was deliberately taking something out of context. Putin made no threats about the use of nuclear weapons in this interview. The president was just talking about the reasons that could make the use of nuclear weapons inevitable.

"These are the reasons that are stated in our relevant documents, which are well known throughout the world. Moreover, everyone in the West deliberately failed to notice his words that it had never occurred to him to use tactical nuclear weapons (in Ukraine), despite the various situations that have developed in the course of the fighting.

"This is a deliberate distortion of the context and an unwillingness to hear President Putin."

(Reporting by Reuters; Wriitng by Andrew Osborn; Editing by Mark Trevelyan)