Putin approves updated nuclear doctrine allowing nuclear weapons use in response to conventional missile assault supported by nuclear power.

The signing of the doctrine, which says that any massive aerial attack on Russia could trigger a nuclear response, reflects Putin’s readiness to threaten the use of the country’s nuclear arsenal to force the West to back down as Moscow presses a slow-moving offensive in Ukraine.

Russia accuses Ukraine of firing U.S.-made missiles, prompting nuclear response warning from President Putin.

Lavrov said he hoped Moscow's new nuclear doctrine, in which President Vladimir Putin lowered the threshold for a nuclear strike, would be attentively read.